igraph Reference Manual

For using the igraph C library

Index

A

add_edge, igraph_add_edge — Adds a single edge to a graph.
add_edges, igraph_add_edges — Adds edges to a graph object.
add_vertices, igraph_add_vertices — Adds vertices to a graph.
adhesion, igraph_adhesion — Graph adhesion, this is (almost) the same as edge connectivity.
adjacency, igraph_adjacency — Creates a graph from an adjacency matrix.
adjacency_spectral_embedding, igraph_adjacency_spectral_embedding — Adjacency spectral embedding
adjacent_triangles, igraph_adjacent_triangles — Count the number of triangles a vertex is part of.
adjlist, igraph_adjlist — Creates a graph from an adjacency list.
adjlist_clear, igraph_adjlist_clear — Removes all edges from an adjacency list.
adjlist_destroy, igraph_adjlist_destroy — Deallocates an adjacency list.
adjlist_get, igraph_adjlist_get — Query a vector in an adjacency list.
adjlist_init, igraph_adjlist_init — Constructs an adjacency list of vertices from a given graph.
adjlist_init_complementer, igraph_adjlist_init_complementer — Adjacency lists for the complementer graph.
adjlist_init_empty, igraph_adjlist_init_empty — Initializes an empty adjacency list.
adjlist_simplify, igraph_adjlist_simplify — Simplifies an adjacency list.
adjlist_size, igraph_adjlist_size — Returns the number of vertices in an adjacency list.
adjlist_sort, igraph_adjlist_sort — Sorts each vector in an adjacency list.
all_minimal_st_separators, igraph_all_minimal_st_separators — List all vertex sets that are minimal (s,t) separators for some s and t.
all_st_cuts, igraph_all_st_cuts — List all edge-cuts between two vertices in a directed graph
all_st_mincuts, igraph_all_st_mincuts — All minimum s-t cuts of a directed graph.
almost_equals, igraph_almost_equals — Compare two double-precision floats with a tolerance.
are_connected, igraph_are_connected — Decides whether two vertices are connected.
arpack_function_t, igraph_arpack_function_t — Type of the ARPACK callback function.
arpack_options_init, igraph_arpack_options_init — Initialize ARPACK options.
arpack_options_t, igraph_arpack_options_t — Options for ARPACK.
arpack_rnsolve, igraph_arpack_rnsolve — ARPACK solver for non-symmetric matrices.
arpack_rssolve, igraph_arpack_rssolve — ARPACK solver for symmetric matrices.
arpack_storage_destroy, igraph_arpack_storage_destroy — Deallocate ARPACK storage.
arpack_storage_init, igraph_arpack_storage_init — Initialize ARPACK storage.
arpack_storage_t, igraph_arpack_storage_t — Storage for ARPACK.
arpack_unpack_complex, igraph_arpack_unpack_complex — Makes the result of the non-symmetric ARPACK solver more readable.
articulation_points, igraph_articulation_points — Finds the articulation points in a graph.
ASSERT, IGRAPH_ASSERT — igraph-specific replacement for assert().
assortativity, igraph_assortativity — Assortativity based on numeric properties of vertices.
assortativity_degree, igraph_assortativity_degree — Assortativity of a graph based on vertex degree.
assortativity_nominal, igraph_assortativity_nominal — Assortativity of a graph based on vertex categories.
astar_heuristic_func_t, igraph_astar_heuristic_func_t — Distance estimator for A* algorithm.
asymmetric_preference_game, igraph_asymmetric_preference_game — Generates a graph with asymmetric vertex types and connection preferences.
atlas, igraph_atlas — Create a small graph from the “Graph Atlas”.
attribute_combination, igraph_attribute_combination — Initialize attribute combination list and add records.
attribute_combination_add, igraph_attribute_combination_add — Add combination record to attribute combination list.
attribute_combination_destroy, igraph_attribute_combination_destroy — Destroy attribute combination list.
attribute_combination_init, igraph_attribute_combination_init — Initialize attribute combination list.
attribute_combination_remove, igraph_attribute_combination_remove — Remove a record from an attribute combination list.
attribute_combination_type_t, igraph_attribute_combination_type_t — The possible types of attribute combinations.
attribute_table_t, igraph_attribute_table_t — Table of functions to perform operations on attributes.
attribute_type_t, igraph_attribute_type_t — The possible types of the attributes.
authority_score, igraph_authority_score — Kleinberg's authority scores.
automorphisms, igraph_automorphisms — Number of automorphisms using Bliss (deprecated alias).
automorphism_group, igraph_automorphism_group — Automorphism group generators using Bliss.
average_local_efficiency, igraph_average_local_efficiency — Calculates the average local efficiency in a network.
average_path_length, igraph_average_path_length — Calculates the average unweighted shortest path length between all vertex pairs.
average_path_length_dijkstra, igraph_average_path_length_dijkstra — Calculates the average weighted shortest path length between all vertex pairs.
avg_nearest_neighbor_degree, igraph_avg_nearest_neighbor_degree — Average neighbor degree.

B

barabasi_aging_game, igraph_barabasi_aging_game — Preferential attachment with aging of vertices.
barabasi_game, igraph_barabasi_game — Generates a graph based on the Barabási-Albert model.
betweenness, igraph_betweenness — Betweenness centrality of some vertices.
betweenness_cutoff, igraph_betweenness_cutoff — Range-limited betweenness centrality.
betweenness_subset, igraph_betweenness_subset — Betweenness centrality for a subset of source and target vertices.
bfs, igraph_bfs — Breadth-first search
bfshandler_t, igraph_bfshandler_t — Callback type for BFS function.
bfs_simple, igraph_bfs_simple — Breadth-first search, single-source version
biadjacency, igraph_biadjacency — Creates a bipartite graph from a bipartite adjacency matrix.
bibcoupling, igraph_bibcoupling — Bibliographic coupling.
biconnected_components, igraph_biconnected_components — Calculates biconnected components.
bipartite_game, igraph_bipartite_game — Generate a bipartite random graph (similar to Erdős-Rényi).
bipartite_game_gnm, igraph_bipartite_game_gnm — Generate a random bipartite graph with a fixed number of edges.
bipartite_game_gnp, igraph_bipartite_game_gnp — Generates a random bipartite graph with a fixed connection probability.
bipartite_projection, igraph_bipartite_projection — Create one or both projections of a bipartite (two-mode) network.
bipartite_projection_size, igraph_bipartite_projection_size — Calculate the number of vertices and edges in the bipartite projections.
blas_ddot, igraph_blas_ddot — Dot product of two vectors.
blas_dgemm, igraph_blas_dgemm — Matrix-matrix multiplication using BLAS.
blas_dgemv, igraph_blas_dgemv — Matrix-vector multiplication using BLAS, vector version.
blas_dgemv_array, igraph_blas_dgemv_array — Matrix-vector multiplication using BLAS, array version.
blas_dnrm2, igraph_blas_dnrm2 — Euclidean norm of a vector.
bliss_info_t, igraph_bliss_info_t — Information about a Bliss run.
bliss_sh_t, igraph_bliss_sh_t — Splitting heuristics for Bliss.
bridges, igraph_bridges — Finds all bridges in a graph.

C

callaway_traits_game, igraph_callaway_traits_game — Simulates a growing network with vertex types.
calloc, igraph_calloc — Allocate memory that can be safely deallocated by igraph functions.
canonical_permutation, igraph_canonical_permutation — Canonical permutation using Bliss.
cattribute_EAB, igraph_cattribute_EAB — Query a boolean edge attribute.
cattribute_EABV, igraph_cattribute_EABV — Query a boolean edge attribute for many edges.
cattribute_EAB_set, igraph_cattribute_EAB_set — Set a boolean edge attribute.
cattribute_EAB_setv, igraph_cattribute_EAB_setv — Set a boolean edge attribute for all edges.
cattribute_EAN, igraph_cattribute_EAN — Query a numeric edge attribute.
cattribute_EANV, igraph_cattribute_EANV — Query a numeric edge attribute for many edges.
cattribute_EAN_set, igraph_cattribute_EAN_set — Set a numeric edge attribute.
cattribute_EAN_setv, igraph_cattribute_EAN_setv — Set a numeric edge attribute for all edges.
cattribute_EAS, igraph_cattribute_EAS — Query a string edge attribute.
cattribute_EASV, igraph_cattribute_EASV — Query a string edge attribute for many edges.
cattribute_EAS_set, igraph_cattribute_EAS_set — Set a string edge attribute.
cattribute_EAS_setv, igraph_cattribute_EAS_setv — Set a string edge attribute for all edges.
cattribute_GAB, igraph_cattribute_GAB — Query a boolean graph attribute.
cattribute_GAB_set, igraph_cattribute_GAB_set — Set a boolean graph attribute.
cattribute_GAN, igraph_cattribute_GAN — Query a numeric graph attribute.
cattribute_GAN_set, igraph_cattribute_GAN_set — Set a numeric graph attribute.
cattribute_GAS, igraph_cattribute_GAS — Query a string graph attribute.
cattribute_GAS_set, igraph_cattribute_GAS_set — Set a string graph attribute.
cattribute_has_attr, igraph_cattribute_has_attr — Checks whether a (graph, vertex or edge) attribute exists.
cattribute_list, igraph_cattribute_list — List all attributes.
cattribute_remove_all, igraph_cattribute_remove_all — Remove all graph/vertex/edge attributes.
cattribute_remove_e, igraph_cattribute_remove_e — Remove an edge attribute.
cattribute_remove_g, igraph_cattribute_remove_g — Remove a graph attribute.
cattribute_remove_v, igraph_cattribute_remove_v — Remove a vertex attribute.
cattribute_VAB, igraph_cattribute_VAB — Query a boolean vertex attribute.
cattribute_VABV, igraph_cattribute_VABV — Query a boolean vertex attribute for many vertices.
cattribute_VAB_set, igraph_cattribute_VAB_set — Set a boolean vertex attribute.
cattribute_VAB_setv, igraph_cattribute_VAB_setv — Set a boolean vertex attribute for all vertices.
cattribute_VAN, igraph_cattribute_VAN — Query a numeric vertex attribute.
cattribute_VANV, igraph_cattribute_VANV — Query a numeric vertex attribute for many vertices.
cattribute_VAN_set, igraph_cattribute_VAN_set — Set a numeric vertex attribute.
cattribute_VAN_setv, igraph_cattribute_VAN_setv — Set a numeric vertex attribute for all vertices.
cattribute_VAS, igraph_cattribute_VAS — Query a string vertex attribute.
cattribute_VASV, igraph_cattribute_VASV — Query a string vertex attribute for many vertices.
cattribute_VAS_set, igraph_cattribute_VAS_set — Set a string vertex attribute.
cattribute_VAS_setv, igraph_cattribute_VAS_setv — Set a string vertex attribute for all vertices.
centralization, igraph_centralization — Calculate the centralization score from the node level scores.
centralization_betweenness, igraph_centralization_betweenness — Calculate vertex betweenness and graph centralization.
centralization_betweenness_tmax, igraph_centralization_betweenness_tmax — Theoretical maximum for graph centralization based on betweenness.
centralization_closeness, igraph_centralization_closeness — Calculate vertex closeness and graph centralization.
centralization_closeness_tmax, igraph_centralization_closeness_tmax — Theoretical maximum for graph centralization based on closeness.
centralization_degree, igraph_centralization_degree — Calculate vertex degree and graph centralization.
centralization_degree_tmax, igraph_centralization_degree_tmax — Theoretical maximum for graph centralization based on degree.
centralization_eigenvector_centrality, igraph_centralization_eigenvector_centrality — Calculate eigenvector centrality scores and graph centralization.
centralization_eigenvector_centrality_tmax, igraph_centralization_eigenvector_centrality_tmax — Theoretical maximum centralization for eigenvector centrality.
CHECK, IGRAPH_CHECK — Checks the return value of a function call.
CHECK_CALLBACK, IGRAPH_CHECK_CALLBACK — Checks the return value of a callback.
circulant, igraph_circulant — Creates a circulant graph.
cited_type_game, igraph_cited_type_game — Simulates a citation based on vertex types.
citing_cited_type_game, igraph_citing_cited_type_game — Simulates a citation network based on vertex types.
cliques, igraph_cliques — Finds all or some cliques in a graph.
cliques_callback, igraph_cliques_callback — Calls a function for each clique in the graph.
clique_handler_t, igraph_clique_handler_t — Type of clique handler functions.
clique_number, igraph_clique_number — Finds the clique number of the graph.
clique_size_hist, igraph_clique_size_hist — Counts cliques of each size in the graph.
closeness, igraph_closeness — Closeness centrality calculations for some vertices.
closeness_cutoff, igraph_closeness_cutoff — Range limited closeness centrality.
clusters, igraph_clusters — Calculates the (weakly or strongly) connected components in a graph (deprecated alias).
cmp_epsilon, igraph_cmp_epsilon — Compare two double-precision floats with a tolerance.
cocitation, igraph_cocitation — Cocitation coupling.
cohesion, igraph_cohesion — Graph cohesion, this is the same as vertex connectivity.
cohesive_blocks, igraph_cohesive_blocks — Identifies the hierarchical cohesive block structure of a graph.
coloring_greedy_t, igraph_coloring_greedy_t — Ordering heuristics for greedy graph coloring.
community_eb_get_merges, igraph_community_eb_get_merges — Calculating the merges, i.e. the dendrogram for an edge betweenness community structure.
community_edge_betweenness, igraph_community_edge_betweenness — Community finding based on edge betweenness.
community_fastgreedy, igraph_community_fastgreedy — Finding community structure by greedy optimization of modularity.
community_fluid_communities, igraph_community_fluid_communities — Community detection based on fluids interacting on the graph.
community_infomap, igraph_community_infomap — Find community structure that minimizes the expected description length of a random walker trajectory.
community_label_propagation, igraph_community_label_propagation — Community detection based on label propagation.
community_leading_eigenvector, igraph_community_leading_eigenvector — Leading eigenvector community finding (proper version).
community_leading_eigenvector_callback_t, igraph_community_leading_eigenvector_callback_t — Callback for the leading eigenvector community finding method.
community_leiden, igraph_community_leiden — Finding community structure using the Leiden algorithm.
community_multilevel, igraph_community_multilevel — Finding community structure by multi-level optimization of modularity.
community_optimal_modularity, igraph_community_optimal_modularity — Calculate the community structure with the highest modularity value.
community_spinglass, igraph_community_spinglass — Community detection based on statistical mechanics.
community_spinglass_single, igraph_community_spinglass_single — Community of a single node based on statistical mechanics.
community_to_membership, igraph_community_to_membership — Creates a membership vector from a community structure dendrogram.
community_voronoi, igraph_community_voronoi — Finds communities using Voronoi partitioning.
community_walktrap, igraph_community_walktrap — Community finding using a random walk based similarity measure.
compare_communities, igraph_compare_communities — Compares community structures using various metrics.
complementer, igraph_complementer — Creates the complementer of a graph.
complex_almost_equals, igraph_complex_almost_equals — Compare two complex numbers with a tolerance.
compose, igraph_compose — Calculates the composition of two graphs.
connected_components, igraph_connected_components — Calculates the (weakly or strongly) connected components in a graph.
connect_neighborhood, igraph_connect_neighborhood — Connects each vertex to its neighborhood.
constraint, igraph_constraint — Burt's constraint scores.
contract_vertices, igraph_contract_vertices — Replace multiple vertices with a single one.
convergence_degree, igraph_convergence_degree — Calculates the convergence degree of each edge in a graph.
convex_hull, igraph_convex_hull — Determines the convex hull of a given set of points in the 2D plane.
copy, igraph_copy — Creates an exact (deep) copy of a graph.
coreness, igraph_coreness — The coreness of the vertices in a graph.
correlated_game, igraph_correlated_game — Generates a random graph correlated to an existing graph.
correlated_pair_game, igraph_correlated_pair_game — Generates pairs of correlated random graphs.
count_automorphisms, igraph_count_automorphisms — Number of automorphisms using Bliss.
count_isomorphisms_vf2, igraph_count_isomorphisms_vf2 — Number of isomorphisms via VF2.
count_multiple, igraph_count_multiple — The multiplicity of some edges in a graph.
count_multiple_1, igraph_count_multiple_1 — The multiplicity of a single edge in a graph.
count_subisomorphisms_vf2, igraph_count_subisomorphisms_vf2 — Number of subgraph isomorphisms using VF2
create, igraph_create — Creates a graph with the specified edges.
create_bipartite, igraph_create_bipartite — Create a bipartite graph.

D

decompose, igraph_decompose — Decomposes a graph into connected components.
decompose_destroy, igraph_decompose_destroy — Frees the contents of a pointer vector holding graphs.
degree, igraph_degree — The degree of some vertices in a graph.
degree_1, igraph_degree_1 — The degree of of a single vertex in the graph.
degree_correlation_vector, igraph_degree_correlation_vector — Degree correlation function.
degree_sequence_game, igraph_degree_sequence_game — Generates a random graph with a given degree sequence.
DELALL, DELALL — Remove all attributes.
DELEA, DELEA — Remove an edge attribute.
DELEAS, DELEAS — Remove all edge attributes.
delete_edges, igraph_delete_edges — Removes edges from a graph.
delete_vertices, igraph_delete_vertices — Removes some vertices (with all their edges) from the graph.
delete_vertices_idx, igraph_delete_vertices_idx — Removes some vertices (with all their edges) from the graph.
DELGA, DELGA — Remove a graph attribute.
DELGAS, DELGAS — Remove all graph attributes.
DELVA, DELVA — Remove a vertex attribute.
DELVAS, DELVAS — Remove all vertex attributes.
density, igraph_density — Calculate the density of a graph.
destroy, igraph_destroy — Frees the memory allocated for a graph object.
deterministic_optimal_imitation, igraph_deterministic_optimal_imitation — Adopt a strategy via deterministic optimal imitation.
de_bruijn, igraph_de_bruijn — Generate a de Bruijn graph.
dfs, igraph_dfs — Depth-first search
dfshandler_t, igraph_dfshandler_t — Callback type for the DFS function.
diameter, igraph_diameter — Calculates the diameter of a graph (longest geodesic).
diameter_dijkstra, igraph_diameter_dijkstra — Calculates the weighted diameter of a graph using Dijkstra's algorithm.
difference, igraph_difference — Calculates the difference of two graphs.
dim_select, igraph_dim_select — Dimensionality selection.
disjoint_union, igraph_disjoint_union — Creates the union of two disjoint graphs.
disjoint_union_many, igraph_disjoint_union_many — The disjoint union of many graphs.
distances, igraph_distances — Length of the shortest paths between vertices.
distances_bellman_ford, igraph_distances_bellman_ford — Weighted shortest path lengths between vertices, allowing negative weights.
distances_cutoff, igraph_distances_cutoff — Length of the shortest paths between vertices, with cutoff.
distances_dijkstra, igraph_distances_dijkstra — Weighted shortest path lengths between vertices.
distances_dijkstra_cutoff, igraph_distances_dijkstra_cutoff — Weighted shortest path lengths between vertices, with cutoff.
distances_floyd_warshall, igraph_distances_floyd_warshall — Weighted all-pairs shortest path lengths with the Floyd-Warshall algorithm.
distances_johnson, igraph_distances_johnson — Weighted shortest path lengths between vertices, using Johnson's algorithm.
diversity, igraph_diversity — Structural diversity index of the vertices.
dominator_tree, igraph_dominator_tree — Calculates the dominator tree of a flowgraph.
dot_product_game, igraph_dot_product_game — Generates a random dot product graph.
dqueue_back, igraph_dqueue_back — Tail of the queue.
dqueue_clear, igraph_dqueue_clear — Remove all elements from the queue.
dqueue_destroy, igraph_dqueue_destroy — Destroy a double ended queue.
dqueue_empty, igraph_dqueue_empty — Decide whether the queue is empty.
dqueue_full, igraph_dqueue_full — Check whether the queue is full.
dqueue_get, igraph_dqueue_get — Access an element in a queue.
dqueue_head, igraph_dqueue_head — Head of the queue.
dqueue_init, igraph_dqueue_init — Initialize a double ended queue (deque).
dqueue_pop, igraph_dqueue_pop — Remove the head.
dqueue_pop_back, igraph_dqueue_pop_back — Removes the tail.
dqueue_push, igraph_dqueue_push — Appends an element.
dqueue_size, igraph_dqueue_size — Number of elements in the queue.
dyad_census, igraph_dyad_census — Dyad census, as defined by Holland and Leinhardt.

E

EAB, EAB — Query a boolean edge attribute.
EABV, EABV — Query a boolean edge attribute for all edges.
EAN, EAN — Query a numeric edge attribute.
EANV, EANV — Query a numeric edge attribute for all edges.
EAS, EAS — Query a string edge attribute.
EASV, EASV — Query a string edge attribute for all edges.
ecc, igraph_ecc — Edge clustering coefficient of some edges.
eccentricity, igraph_eccentricity — Eccentricity of some vertices.
eccentricity_dijkstra, igraph_eccentricity_dijkstra — Eccentricity of some vertices, using weighted edges.
ecount, igraph_ecount — The number of edges in a graph.
ECOUNT_MAX, IGRAPH_ECOUNT_MAX — The maximum number of edges supported in igraph graphs.
edge, igraph_edge — Returns the head and tail vertices of an edge.
edges, igraph_edges — Gives the head and tail vertices of a series of edges.
edge_betweenness, igraph_edge_betweenness — Betweenness centrality of the edges.
edge_betweenness_cutoff, igraph_edge_betweenness_cutoff — Range-limited betweenness centrality of the edges.
edge_betweenness_subset, igraph_edge_betweenness_subset — Edge betweenness centrality for a subset of source and target vertices.
edge_connectivity, igraph_edge_connectivity — The minimum edge connectivity in a graph.
edge_disjoint_paths, igraph_edge_disjoint_paths — The maximum number of edge-disjoint paths between two vertices.
eigenvector_centrality, igraph_eigenvector_centrality — Eigenvector centrality of the vertices.
eit_create, igraph_eit_create — Creates an edge iterator from an edge selector.
eit_destroy, igraph_eit_destroy — Destroys an edge iterator.
EIT_END, IGRAPH_EIT_END — Are we at the end?
EIT_GET, IGRAPH_EIT_GET — Query an edge iterator.
EIT_NEXT, IGRAPH_EIT_NEXT — Next edge.
EIT_RESET, IGRAPH_EIT_RESET — Reset an edge iterator.
EIT_SIZE, IGRAPH_EIT_SIZE — Number of edges in the iterator.
empty, igraph_empty — Creates an empty graph with some vertices and no edges.
empty_attrs, igraph_empty_attrs — Creates an empty graph with some vertices, no edges and some graph attributes.
enter_safelocale, igraph_enter_safelocale — Temporarily set the C locale.
erdos_renyi_game, igraph_erdos_renyi_game — Generates a random (Erdős-Rényi) graph.
erdos_renyi_game_gnm, igraph_erdos_renyi_game_gnm — Generates a random (Erdős-Rényi) graph with a fixed number of edges.
erdos_renyi_game_gnp, igraph_erdos_renyi_game_gnp — Generates a random (Erdős-Rényi) graph with fixed edge probabilities.
ERROR, IGRAPH_ERROR — Triggers an error.
error, igraph_error — Reports an error.
ERRORF, IGRAPH_ERRORF — Triggers an error, with printf-like syntax.
errorf, igraph_errorf — Reports an error, printf-like version.
error_handler_abort, igraph_error_handler_abort — Abort program in case of error.
error_handler_ignore, igraph_error_handler_ignore — Ignore errors.
error_handler_printignore, igraph_error_handler_printignore — Print and ignore errors.
error_handler_t, igraph_error_handler_t — The type of error handler functions.
error_t, igraph_error_t — Return type for functions returning an error code.
error_type_t, igraph_error_type_t — Error code type.
ess_1, igraph_ess_1 — Immediate version of the single edge edge selector.
ess_all, igraph_ess_all — Edge set, all edges (immediate version).
ess_none, igraph_ess_none — Immediate empty edge selector.
ess_range, igraph_ess_range — Immediate version of the sequence edge selector.
ess_seq, igraph_ess_seq — Immediate version of the sequence edge selector, with inclusive endpoints.
ess_vector, igraph_ess_vector — Immediate vector view edge selector.
establishment_game, igraph_establishment_game — Generates a graph with a simple growing model with vertex types.
es_1, igraph_es_1 — Edge selector containing a single edge.
es_all, igraph_es_all — Edge set, all edges.
es_as_vector, igraph_es_as_vector — Transform edge selector into vector.
es_copy, igraph_es_copy — Creates a copy of an edge selector.
es_destroy, igraph_es_destroy — Destroys an edge selector object.
es_incident, igraph_es_incident — Edges incident on a given vertex.
es_is_all, igraph_es_is_all — Check whether an edge selector includes all edges.
es_none, igraph_es_none — Empty edge selector.
es_pairs, igraph_es_pairs — Edge selector, multiple edges defined by their endpoints in a vector.
es_pairs_small, igraph_es_pairs_small — Edge selector, multiple edges defined by their endpoints as arguments.
es_path, igraph_es_path — Edge selector, edge IDs on a path.
es_range, igraph_es_range — Edge selector, a sequence of edge IDs.
es_seq, igraph_es_seq — Edge selector, a sequence of edge IDs, with inclusive endpoints (deprecated).
es_size, igraph_es_size — Returns the size of the edge selector.
es_type, igraph_es_type — Returns the type of the edge selector.
es_vector, igraph_es_vector — Handle a vector as an edge selector.
es_vector_copy, igraph_es_vector_copy — Edge set, based on a vector, with copying.
eulerian_cycle, igraph_eulerian_cycle — Finds an Eulerian cycle.
eulerian_path, igraph_eulerian_path — Finds an Eulerian path.
even_tarjan_reduction, igraph_even_tarjan_reduction — Even-Tarjan reduction of a graph.
exit_safelocale, igraph_exit_safelocale — Temporarily set the C locale.
expand_path_to_pairs, igraph_expand_path_to_pairs — Helper function to convert a sequence of vertex IDs describing a path into a "pairs" vector.
extended_chordal_ring, igraph_extended_chordal_ring — Create an extended chordal ring.

F

famous, igraph_famous — Create a famous graph by simply providing its name.
FATAL, IGRAPH_FATAL — Triggers a fatal error.
fatal, igraph_fatal — Triggers a fatal error.
FATALF, IGRAPH_FATALF — Triggers a fatal error, with printf-like syntax.
fatalf, igraph_fatalf — Triggers a fatal error, printf-like syntax.
fatal_handler_abort, igraph_fatal_handler_abort — Abort program in case of fatal error.
fatal_handler_t, igraph_fatal_handler_t — The type of igraph fatal error handler functions.
feedback_arc_set, igraph_feedback_arc_set — Feedback arc set of a graph using exact or heuristic methods.
FINALLY, IGRAPH_FINALLY — Registers an object for deallocation.
FINALLY_CLEAN, IGRAPH_FINALLY_CLEAN — Signals clean deallocation of objects.
FINALLY_FREE, IGRAPH_FINALLY_FREE — Deallocates objects registered at the current level.
forest_fire_game, igraph_forest_fire_game — Generates a network according to the “forest fire game”.
free, igraph_free — Deallocate memory that was allocated by igraph functions.
FROM, IGRAPH_FROM — The source vertex of an edge.
from_hrg_dendrogram, igraph_from_hrg_dendrogram — Create a graph representation of the dendrogram of a hierarchical random graph model.
from_prufer, igraph_from_prufer — Generates a tree from a Prüfer sequence.
full, igraph_full — Creates a full graph (directed or undirected, with or without loops).
full_bipartite, igraph_full_bipartite — Create a full bipartite network.
full_citation, igraph_full_citation — Creates a full citation graph.
full_multipartite, igraph_full_multipartite — Create a full multipartite graph.
fundamental_cycles, igraph_fundamental_cycles — Finds a fundamental cycle basis.

G

GAB, GAB — Query a boolean graph attribute.
GAN, GAN — Query a numeric graph attribute.
GAS, GAS — Query a string graph attribute.
generalized_petersen, igraph_generalized_petersen — Creates a Generalized Petersen graph.
get_adjacency, igraph_get_adjacency — The adjacency matrix of a graph.
get_adjacency_sparse, igraph_get_adjacency_sparse — Returns the adjacency matrix of a graph in a sparse matrix format.
get_all_eids_between, igraph_get_all_eids_between — Returns all edge IDs between a pair of vertices.
get_all_shortest_paths, igraph_get_all_shortest_paths — All shortest paths (geodesics) from a vertex.
get_all_shortest_paths_dijkstra, igraph_get_all_shortest_paths_dijkstra — All weighted shortest paths (geodesics) from a vertex.
get_all_simple_paths, igraph_get_all_simple_paths — List all simple paths from one source.
get_biadjacency, igraph_get_biadjacency — Convert a bipartite graph into a bipartite adjacency matrix.
get_edgelist, igraph_get_edgelist — The list of edges in a graph.
get_eid, igraph_get_eid — Get the edge ID from the end points of an edge.
get_eids, igraph_get_eids — Return edge IDs based on the adjacent vertices.
get_incidence, igraph_get_incidence — Convert a bipartite graph into a bipartite adjacency matrix (deprecated alias).
get_isomorphisms_vf2, igraph_get_isomorphisms_vf2 — Collect all isomorphic mappings of two graphs.
get_isomorphisms_vf2_callback, igraph_get_isomorphisms_vf2_callback — The generic VF2 interface
get_k_shortest_paths, igraph_get_k_shortest_paths — k shortest paths between two vertices.
get_laplacian, igraph_get_laplacian — Returns the Laplacian matrix of a graph.
get_laplacian_sparse, igraph_get_laplacian_sparse — Returns the Laplacian of a graph in a sparse matrix format.
get_shortest_path, igraph_get_shortest_path — Shortest path from one vertex to another one.
get_shortest_paths, igraph_get_shortest_paths — Shortest paths from a vertex.
get_shortest_paths_bellman_ford, igraph_get_shortest_paths_bellman_ford — Weighted shortest paths from a vertex, allowing negative weights.
get_shortest_paths_dijkstra, igraph_get_shortest_paths_dijkstra — Weighted shortest paths from a vertex.
get_shortest_path_astar, igraph_get_shortest_path_astar — A* gives the shortest path from one vertex to another, with heuristic.
get_shortest_path_bellman_ford, igraph_get_shortest_path_bellman_ford — Weighted shortest path from one vertex to another one (Bellman-Ford).
get_shortest_path_dijkstra, igraph_get_shortest_path_dijkstra — Weighted shortest path from one vertex to another one (Dijkstra).
get_sparsemat, igraph_get_sparsemat — Converts an igraph graph to a sparse matrix (deprecated).
get_stochastic, igraph_get_stochastic — Stochastic adjacency matrix of a graph.
get_stochastic_sparse, igraph_get_stochastic_sparse — The stochastic adjacency matrix of a graph.
get_stochastic_sparsemat, igraph_get_stochastic_sparsemat — Stochastic adjacency matrix of a graph (deprecated).
get_subisomorphisms_vf2, igraph_get_subisomorphisms_vf2 — Return all subgraph isomorphic mappings.
get_subisomorphisms_vf2_callback, igraph_get_subisomorphisms_vf2_callback — Generic VF2 function for subgraph isomorphism problems.
get_widest_path, igraph_get_widest_path — Widest path from one vertex to another one.
get_widest_paths, igraph_get_widest_paths — Widest paths from a single vertex.
girth, igraph_girth — The girth of a graph is the length of the shortest cycle in it.
global_efficiency, igraph_global_efficiency — Calculates the global efficiency of a network.
gomory_hu_tree, igraph_gomory_hu_tree — Gomory-Hu tree of a graph.
graphlets, igraph_graphlets — Calculate graphlets basis and project the graph on it
graphlets_candidate_basis, igraph_graphlets_candidate_basis — Calculate a candidate graphlets basis
graphlets_project, igraph_graphlets_project — Project a graph on a graphlets basis
graph_center, igraph_graph_center — Central vertices of a graph.
graph_center_dijkstra, igraph_graph_center_dijkstra — Central vertices of a graph, using weighted edges.
graph_count, igraph_graph_count — The number of unlabelled graphs on the given number of vertices.
graph_power, igraph_graph_power — The kth power of a graph.
grg_game, igraph_grg_game — Generates a geometric random graph.
growing_random_game, igraph_growing_random_game — Generates a growing random graph.

H

harmonic_centrality, igraph_harmonic_centrality — Harmonic centrality for some vertices.
harmonic_centrality_cutoff, igraph_harmonic_centrality_cutoff — Range limited harmonic centrality.
has_multiple, igraph_has_multiple — Check whether the graph has at least one multiple edge.
heap_clear, igraph_heap_clear — Removes all elements from a heap.
heap_delete_top, igraph_heap_delete_top — Removes and returns the top element.
heap_destroy, igraph_heap_destroy — Destroys an initialized heap object.
heap_empty, igraph_heap_empty — Decides whether a heap object is empty.
heap_init, igraph_heap_init — Initializes an empty heap object.
heap_init_array, igraph_heap_init_array — Build a heap from an array.
heap_push, igraph_heap_push — Add an element.
heap_reserve, igraph_heap_reserve — Reserves memory for a heap.
heap_size, igraph_heap_size — Number of elements in the heap.
heap_top, igraph_heap_top — Top element.
hexagonal_lattice, igraph_hexagonal_lattice — A hexagonal lattice with the given shape.
hrg_consensus, igraph_hrg_consensus — Calculate a consensus tree for a HRG.
hrg_create, igraph_hrg_create — Create a HRG from an igraph graph.
hrg_dendrogram, igraph_hrg_dendrogram — Create a dendrogram from a hierarchical random graph.
hrg_destroy, igraph_hrg_destroy — Deallocate memory for an HRG.
hrg_fit, igraph_hrg_fit — Fit a hierarchical random graph model to a network.
hrg_game, igraph_hrg_game — Generate a hierarchical random graph.
hrg_init, igraph_hrg_init — Allocate memory for a HRG.
hrg_predict, igraph_hrg_predict — Predict missing edges in a graph, based on HRG models.
hrg_resize, igraph_hrg_resize — Resize a HRG.
hrg_sample, igraph_hrg_sample — Sample from a hierarchical random graph model.
hrg_size, igraph_hrg_size — Returns the size of the HRG, the number of leaf nodes.
hrg_t, igraph_hrg_t — Data structure to store a hierarchical random graph.
hsbm_game, igraph_hsbm_game — Hierarchical stochastic block model.
hsbm_list_game, igraph_hsbm_list_game — Hierarchical stochastic block model, more general version.
hub_and_authority_scores, igraph_hub_and_authority_scores — Kleinberg's hub and authority scores.
hub_score, igraph_hub_score — Kleinberg's hub scores.

I

igraph_bool_t, Atomic data types
IGRAPH_INTEGER_MAX, Atomic data types
IGRAPH_INTEGER_MIN, Atomic data types
igraph_integer_t, Atomic data types
igraph_real_t, Atomic data types
IGRAPH_UINT_MAX, Atomic data types
IGRAPH_UINT_MIN, Atomic data types
igraph_uint_t, Atomic data types
incidence, igraph_incidence — Creates a bipartite graph from a bipartite adjacency matrix (deprecated alias).
incident, igraph_incident — Gives the incident edges of a vertex.
inclist_clear, igraph_inclist_clear — Removes all edges from an incidence list.
inclist_destroy, igraph_inclist_destroy — Frees all memory allocated for an incidence list.
inclist_get, igraph_inclist_get — Query a vector in an incidence list.
inclist_init, igraph_inclist_init — Initializes an incidence list.
inclist_size, igraph_inclist_size — Returns the number of vertices in an incidence list.
independence_number, igraph_independence_number — Finds the independence number of the graph.
independent_vertex_sets, igraph_independent_vertex_sets — Finds all independent vertex sets in a graph.
induced_subgraph, igraph_induced_subgraph — Creates a subgraph induced by the specified vertices.
induced_subgraph_map, igraph_induced_subgraph_map — Creates an induced subraph and returns the mapping from the original.
intersection, igraph_intersection — Collect the common edges from two graphs.
intersection_many, igraph_intersection_many — The intersection of more than two graphs.
invalidate_cache, igraph_invalidate_cache — Invalidates the internal cache of an igraph graph.
isoclass, igraph_isoclass — Determine the isomorphism class of small graphs.
isoclass_create, igraph_isoclass_create — Creates a graph from the given isomorphism class.
isoclass_subgraph, igraph_isoclass_subgraph — The isomorphism class of a subgraph of a graph.
isocompat_t, igraph_isocompat_t — Callback type, called to check whether two vertices or edges are compatible
isohandler_t, igraph_isohandler_t — Callback type, called when an isomorphism was found
isomorphic, igraph_isomorphic — Are two graphs isomorphic?
isomorphic_34, igraph_isomorphic_34 — Graph isomorphism for 3-4 vertices (deprecated).
isomorphic_bliss, igraph_isomorphic_bliss — Graph isomorphism via Bliss.
isomorphic_function_vf2, igraph_isomorphic_function_vf2 — The generic VF2 interface (deprecated alias).
isomorphic_vf2, igraph_isomorphic_vf2 — Isomorphism via VF2.
is_acyclic, igraph_is_acyclic — Checks whether a graph is acyclic or not.
is_bigraphical, igraph_is_bigraphical — Is there a bipartite graph with the given bi-degree-sequence?
is_bipartite, igraph_is_bipartite — Check whether a graph is bipartite.
is_chordal, igraph_is_chordal — Decides whether a graph is chordal.
is_connected, igraph_is_connected — Decides whether the graph is (weakly or strongly) connected.
is_dag, igraph_is_dag — Checks whether a graph is a directed acyclic graph (DAG).
is_directed, igraph_is_directed — Is this a directed graph?
is_eulerian, igraph_is_eulerian — Checks whether an Eulerian path or cycle exists.
is_forest, igraph_is_forest — Decides whether the graph is a forest.
is_graphical, igraph_is_graphical — Is there a graph with the given degree sequence?
is_loop, igraph_is_loop — Find the loop edges in a graph.
is_matching, igraph_is_matching — Checks whether the given matching is valid for the given graph.
is_maximal_matching, igraph_is_maximal_matching — Checks whether a matching in a graph is maximal.
is_minimal_separator, igraph_is_minimal_separator — Decides whether a set of vertices is a minimal separator.
is_multiple, igraph_is_multiple — Find the multiple edges in a graph.
is_mutual, igraph_is_mutual — Check whether some edges of a directed graph are mutual.
is_perfect, igraph_is_perfect — Checks if the graph is perfect.
is_same_graph, igraph_is_same_graph — Are two graphs identical as labelled graphs?
is_separator, igraph_is_separator — Would removing this set of vertices disconnect the graph?
is_simple, igraph_is_simple — Decides whether the input graph is a simple graph.
is_tree, igraph_is_tree — Decides whether the graph is a tree.

J

joint_degree_distribution, igraph_joint_degree_distribution — The joint degree distribution of a graph.
joint_degree_matrix, igraph_joint_degree_matrix — The joint degree matrix of a graph.
joint_type_distribution, igraph_joint_type_distribution — Mixing matrix for vertex categories.

K

kary_tree, igraph_kary_tree — Creates a k-ary tree in which almost all vertices have k children.
kautz, igraph_kautz — Generate a Kautz graph.
k_regular_game, igraph_k_regular_game — Generates a random graph where each vertex has the same degree.

L

lapack_dgeev, igraph_lapack_dgeev — Eigenvalues and optionally eigenvectors of a non-symmetric matrix.
lapack_dgeevx, igraph_lapack_dgeevx — Eigenvalues/vectors of nonsymmetric matrices, expert mode.
lapack_dgesv, igraph_lapack_dgesv — Solve system of linear equations with LU factorization.
lapack_dgetrf, igraph_lapack_dgetrf — LU factorization of a general M-by-N matrix.
lapack_dgetrs, igraph_lapack_dgetrs — Solve general system of linear equations using LU factorization.
lapack_dsyevr, igraph_lapack_dsyevr — Selected eigenvalues and optionally eigenvectors of a symmetric matrix.
laplacian, igraph_laplacian — Returns the Laplacian matrix of a graph (deprecated).
laplacian_normalization_t, igraph_laplacian_normalization_t — Normalization methods for a Laplacian matrix.
laplacian_spectral_embedding, igraph_laplacian_spectral_embedding — Spectral embedding of the Laplacian of a graph
largest_cliques, igraph_largest_cliques — Finds the largest clique(s) in a graph.
largest_independent_vertex_sets, igraph_largest_independent_vertex_sets — Finds the largest independent vertex set(s) in a graph.
largest_weighted_cliques, igraph_largest_weighted_cliques — Finds the largest weight clique(s) in a graph.
lastcit_game, igraph_lastcit_game — Simulates a citation network, based on time passed since the last citation.
lattice, igraph_lattice — Arbitrary dimensional square lattices (deprecated).
layout_bipartite, igraph_layout_bipartite — Simple layout for bipartite graphs.
layout_circle, igraph_layout_circle — Places the vertices uniformly on a circle in arbitrary order.
layout_davidson_harel, igraph_layout_davidson_harel — Davidson-Harel layout algorithm.
layout_drl, igraph_layout_drl — The DrL layout generator
layout_drl_3d, igraph_layout_drl_3d — The DrL layout generator, 3d version.
layout_drl_default_t, igraph_layout_drl_default_t — Predefined parameter templates for the DrL layout generator
layout_drl_options_init, igraph_layout_drl_options_init — Initialize parameters for the DrL layout generator
layout_drl_options_t, igraph_layout_drl_options_t — Parameters for the DrL layout generator
layout_fruchterman_reingold, igraph_layout_fruchterman_reingold — Places the vertices on a plane according to the Fruchterman-Reingold algorithm.
layout_fruchterman_reingold_3d, igraph_layout_fruchterman_reingold_3d — 3D Fruchterman-Reingold algorithm.
layout_gem, igraph_layout_gem — Layout graph according to GEM algorithm.
layout_graphopt, igraph_layout_graphopt — Optimizes vertex layout via the graphopt algorithm.
layout_grid, igraph_layout_grid — Places the vertices on a regular grid on the plane.
layout_grid_3d, igraph_layout_grid_3d — Places the vertices on a regular grid in the 3D space.
layout_kamada_kawai, igraph_layout_kamada_kawai — Places the vertices on a plane according to the Kamada-Kawai algorithm.
layout_kamada_kawai_3d, igraph_layout_kamada_kawai_3d — 3D version of the Kamada-Kawai layout generator.
layout_lgl, igraph_layout_lgl — Force based layout algorithm for large graphs.
layout_mds, igraph_layout_mds — Place the vertices on a plane using multidimensional scaling.
layout_merge_dla, igraph_layout_merge_dla — Merges multiple layouts by using a DLA algorithm.
layout_random, igraph_layout_random — Places the vertices uniform randomly on a plane.
layout_random_3d, igraph_layout_random_3d — Places the vertices uniform randomly in a cube.
layout_reingold_tilford, igraph_layout_reingold_tilford — Reingold-Tilford layout for tree graphs.
layout_reingold_tilford_circular, igraph_layout_reingold_tilford_circular — Circular Reingold-Tilford layout for trees.
layout_sphere, igraph_layout_sphere — Places vertices (more or less) uniformly on a sphere.
layout_star, igraph_layout_star — Generates a star-like layout.
layout_sugiyama, igraph_layout_sugiyama — Sugiyama layout algorithm for layered directed acyclic graphs.
layout_umap, igraph_layout_umap — Layout using Uniform Manifold Approximation and Projection (UMAP).
layout_umap_3d, igraph_layout_umap_3d — 3D layout using UMAP.
layout_umap_compute_weights, igraph_layout_umap_compute_weights — Compute weights for a UMAP layout starting from distances.
lazy_adjlist_clear, igraph_lazy_adjlist_clear — Removes all edges from a lazy adjacency list.
lazy_adjlist_destroy, igraph_lazy_adjlist_destroy — Deallocate a lazt adjacency list.
lazy_adjlist_get, igraph_lazy_adjlist_get — Query neighbor vertices.
lazy_adjlist_has, igraph_lazy_adjlist_has — Are adjacenct vertices already stored in a lazy adjacency list?
lazy_adjlist_init, igraph_lazy_adjlist_init — Initializes a lazy adjacency list.
lazy_adjlist_size, igraph_lazy_adjlist_size — Returns the number of vertices in a lazy adjacency list.
lazy_inclist_clear, igraph_lazy_inclist_clear — Removes all edges from a lazy incidence list.
lazy_inclist_destroy, igraph_lazy_inclist_destroy — Deallocates a lazy incidence list.
lazy_inclist_get, igraph_lazy_inclist_get — Query incident edges.
lazy_inclist_has, igraph_lazy_inclist_has — Are incident edges already stored in a lazy inclist?
lazy_inclist_init, igraph_lazy_inclist_init — Initializes a lazy incidence list of edges.
lazy_inclist_size, igraph_lazy_inclist_size — Returns the number of vertices in a lazy incidence list.
lcf, igraph_lcf — Creates a graph from LCF notation.
lcf_vector, igraph_lcf_vector — Creates a graph from LCF notation.
le_community_to_membership, igraph_le_community_to_membership — Vertex membership from the leading eigenvector community structure.
linegraph, igraph_linegraph — Create the line graph of a graph.
list_triangles, igraph_list_triangles — Find all triangles in a graph.
local_efficiency, igraph_local_efficiency — Calculates the local efficiency around each vertex in a network.
local_scan_0, igraph_local_scan_0 — Local scan-statistics, k=0
local_scan_0_them, igraph_local_scan_0_them — Local THEM scan-statistics, k=0
local_scan_1_ecount, igraph_local_scan_1_ecount — Local scan-statistics, k=1, edge count and sum of weights
local_scan_1_ecount_them, igraph_local_scan_1_ecount_them — Local THEM scan-statistics, k=1, edge count and sum of weights
local_scan_k_ecount, igraph_local_scan_k_ecount — Sum the number of edges or the weights in k-neighborhood of every vertex.
local_scan_k_ecount_them, igraph_local_scan_k_ecount_them — Local THEM scan-statistics, edge count or sum of weights.
local_scan_neighborhood_ecount, igraph_local_scan_neighborhood_ecount — Local scan-statistics with pre-calculated neighborhoods
local_scan_subset_ecount, igraph_local_scan_subset_ecount — Local scan-statistics of subgraphs induced by subsets of vertices.

M

malloc, igraph_malloc — Allocate memory that can be safely deallocated by igraph functions.
MATRIX, MATRIX — Accessing an element of a matrix.
matrix_add, igraph_matrix_add — Add two matrices.
matrix_add_cols, igraph_matrix_add_cols — Adds columns to a matrix.
matrix_add_constant, igraph_matrix_add_constant — Add a constant to every element.
matrix_add_rows, igraph_matrix_add_rows — Adds rows to a matrix.
matrix_all_almost_e, igraph_matrix_all_almost_e — Are all elements almost equal?
matrix_all_e, igraph_matrix_all_e — Are all elements equal?
matrix_all_g, igraph_matrix_all_g — Are all elements greater?
matrix_all_ge, igraph_matrix_all_ge — Are all elements greater or equal?
matrix_all_l, igraph_matrix_all_l — Are all elements less?
matrix_all_le, igraph_matrix_all_le — Are all elements less or equal?
matrix_as_sparsemat, igraph_matrix_as_sparsemat — Converts a dense matrix to a sparse matrix.
matrix_capacity, igraph_matrix_capacity — Returns the number of elements allocated for a matrix.
matrix_cbind, igraph_matrix_cbind — Combine matrices columnwise.
matrix_colsum, igraph_matrix_colsum — Columnwise sum.
matrix_complex_all_almost_e, igraph_matrix_complex_all_almost_e — Are all elements almost equal?
matrix_complex_create, igraph_matrix_complex_create — Creates a complex matrix from a real and imaginary part.
matrix_complex_create_polar, igraph_matrix_complex_create_polar — Creates a complex matrix from a magnitude and an angle.
matrix_complex_imag, igraph_matrix_complex_imag — Gives the imaginary part of a complex matrix.
matrix_complex_real, igraph_matrix_complex_real — Gives the real part of a complex matrix.
matrix_complex_realimag, igraph_matrix_complex_realimag — Gives the real and imaginary parts of a complex matrix.
matrix_complex_zapsmall, igraph_matrix_complex_zapsmall — Replaces small elements of a complex matrix by exact zeros.
matrix_contains, igraph_matrix_contains — Search for an element.
matrix_copy, igraph_matrix_copy — Copies a matrix (deprecated alias).
matrix_copy_to, igraph_matrix_copy_to — Copies a matrix to a regular C array.
matrix_destroy, igraph_matrix_destroy — Destroys a matrix object.
matrix_div_elements, igraph_matrix_div_elements — Elementwise division.
matrix_e, igraph_matrix_e — Extract an element from a matrix (deprecated alias).
matrix_empty, igraph_matrix_empty — Is the matrix empty?
matrix_e_ptr, igraph_matrix_e_ptr — Pointer to an element of a matrix.
matrix_fill, igraph_matrix_fill — Fill with an element.
matrix_get, igraph_matrix_get — Extract an element from a matrix.
matrix_get_col, igraph_matrix_get_col — Select a column.
matrix_get_ptr, igraph_matrix_get_ptr — Pointer to an element of a matrix.
matrix_get_row, igraph_matrix_get_row — Extract a row.
matrix_init, igraph_matrix_init — Initializes a matrix.
matrix_init_array, igraph_matrix_init_array — Initializes a matrix from an ordinary C array (constructor).
matrix_init_copy, igraph_matrix_init_copy — Copies a matrix.
matrix_isnull, igraph_matrix_isnull — Checks for a null matrix.
matrix_is_symmetric, igraph_matrix_is_symmetric — Is the matrix symmetric?
matrix_max, igraph_matrix_max — Largest element of a matrix.
matrix_maxdifference, igraph_matrix_maxdifference — Maximum absolute difference between two matrices.
matrix_min, igraph_matrix_min — Smallest element of a matrix.
matrix_minmax, igraph_matrix_minmax — Minimum and maximum elements of a matrix.
matrix_mul_elements, igraph_matrix_mul_elements — Elementwise matrix multiplication.
matrix_ncol, igraph_matrix_ncol — The number of columns in a matrix.
matrix_nrow, igraph_matrix_nrow — The number of rows in a matrix.
matrix_null, igraph_matrix_null — Sets all elements in a matrix to zero.
matrix_prod, igraph_matrix_prod — Product of all matrix elements.
matrix_rbind, igraph_matrix_rbind — Combine two matrices rowwise.
matrix_remove_col, igraph_matrix_remove_col — Removes a column from a matrix.
matrix_remove_row, igraph_matrix_remove_row — Remove a row.
matrix_resize, igraph_matrix_resize — Resizes a matrix.
matrix_resize_min, igraph_matrix_resize_min — Deallocates unused memory for a matrix.
matrix_rowsum, igraph_matrix_rowsum — Rowwise sum.
matrix_scale, igraph_matrix_scale — Multiplies each element of the matrix by a constant.
matrix_search, igraph_matrix_search — Search from a given position.
matrix_select_cols, igraph_matrix_select_cols — Select some columns of a matrix.
matrix_select_rows, igraph_matrix_select_rows — Select some rows of a matrix.
matrix_select_rows_cols, igraph_matrix_select_rows_cols — Select some rows and columns of a matrix.
matrix_set, igraph_matrix_set — Set an element.
matrix_set_col, igraph_matrix_set_col — Set a column from a vector.
matrix_set_row, igraph_matrix_set_row — Set a row from a vector.
matrix_size, igraph_matrix_size — The number of elements in a matrix.
matrix_sub, igraph_matrix_sub — Difference of two matrices.
matrix_sum, igraph_matrix_sum — Sum of elements.
matrix_swap, igraph_matrix_swap — Swap two matrices.
matrix_swap_cols, igraph_matrix_swap_cols — Swap two columns.
matrix_swap_rows, igraph_matrix_swap_rows — Swap two rows.
matrix_transpose, igraph_matrix_transpose — Transpose of a matrix.
matrix_update, igraph_matrix_update — Update from another matrix.
matrix_view, igraph_matrix_view — Creates a matrix view into an existing array.
matrix_view_from_vector, igraph_matrix_view_from_vector — Creates a matrix view that treats an existing vector as a matrix.
matrix_which_max, igraph_matrix_which_max — Indices of the largest element.
matrix_which_min, igraph_matrix_which_min — Indices of the smallest element.
matrix_which_minmax, igraph_matrix_which_minmax — Indices of the minimum and maximum elements.
matrix_zapsmall, igraph_matrix_zapsmall — Replaces small elements of a matrix by exact zeros.
maxdegree, igraph_maxdegree — The maximum degree in a graph (or set of vertices).
maxflow, igraph_maxflow — Maximum network flow between a pair of vertices.
maxflow_stats_t, igraph_maxflow_stats_t — Data structure holding statistics from the push-relabel maximum flow solver.
maxflow_value, igraph_maxflow_value — Maximum flow in a network with the push/relabel algorithm.
maximal_cliques, igraph_maximal_cliques — Finds all maximal cliques in a graph.
maximal_cliques_callback, igraph_maximal_cliques_callback — Finds maximal cliques in a graph and calls a function for each one.
maximal_cliques_count, igraph_maximal_cliques_count — Count the number of maximal cliques in a graph.
maximal_cliques_file, igraph_maximal_cliques_file — Find maximal cliques and write them to a file.
maximal_cliques_hist, igraph_maximal_cliques_hist — Counts the number of maximal cliques of each size in a graph.
maximal_cliques_subset, igraph_maximal_cliques_subset — Maximal cliques for a subset of initial vertices.
maximal_independent_vertex_sets, igraph_maximal_independent_vertex_sets — Finds all maximal independent vertex sets of a graph.
maximum_bipartite_matching, igraph_maximum_bipartite_matching — Calculates a maximum matching in a bipartite graph.
maximum_cardinality_search, igraph_maximum_cardinality_search — Maximum cardinality search.
mincut, igraph_mincut — Calculates the minimum cut in a graph.
mincut_value, igraph_mincut_value — The minimum edge cut in a graph.
minimum_cycle_basis, igraph_minimum_cycle_basis — Computes a minimum weight cycle basis.
minimum_size_separators, igraph_minimum_size_separators — Find all minimum size separating vertex sets.
minimum_spanning_tree, igraph_minimum_spanning_tree — Calculates one minimum spanning tree of a graph.
minimum_spanning_tree_prim, igraph_minimum_spanning_tree_prim — Calculates one minimum spanning tree of a weighted graph.
minimum_spanning_tree_unweighted, igraph_minimum_spanning_tree_unweighted — Calculates one minimum spanning tree of an unweighted graph.
modularity, igraph_modularity — Calculates the modularity of a graph with respect to some clusters or vertex types.
modularity_matrix, igraph_modularity_matrix — Calculates the modularity matrix.
moran_process, igraph_moran_process — The Moran process in a network setting.
motifs_handler_t, igraph_motifs_handler_t — Callback type for igraph_motifs_randesu_callback.
motifs_randesu, igraph_motifs_randesu — Count the number of motifs in a graph.
motifs_randesu_callback, igraph_motifs_randesu_callback — Finds motifs in a graph and calls a function for each of them.
motifs_randesu_estimate, igraph_motifs_randesu_estimate — Estimate the total number of motifs in a graph.
motifs_randesu_no, igraph_motifs_randesu_no — Count the total number of motifs in a graph.

N

neighborhood, igraph_neighborhood — Calculate the neighborhood of vertices.
neighborhood_graphs, igraph_neighborhood_graphs — Create graphs from the neighborhood(s) of some vertex/vertices.
neighborhood_size, igraph_neighborhood_size — Calculates the size of the neighborhood of a given vertex.
neighbors, igraph_neighbors — Adjacent vertices to a vertex.

O

OTHER, IGRAPH_OTHER — The other endpoint of an edge.

P

pagerank, igraph_pagerank — Calculates the Google PageRank for the specified vertices.
pagerank_algo_t, igraph_pagerank_algo_t — PageRank algorithm implementation.
path_length_hist, igraph_path_length_hist — Create a histogram of all shortest path lengths.
permute_vertices, igraph_permute_vertices — Permute the vertices.
personalized_pagerank, igraph_personalized_pagerank — Calculates the personalized Google PageRank for the specified vertices.
personalized_pagerank_vs, igraph_personalized_pagerank_vs — Calculates the personalized Google PageRank for the specified vertices.
plfit_result_calculate_p_value, igraph_plfit_result_calculate_p_value — Calculates the p-value of a fitted power-law model.
plfit_result_t, igraph_plfit_result_t — Result of fitting a power-law distribution to a vector.
power_law_fit, igraph_power_law_fit — Fits a power-law distribution to a vector of numbers.
preference_game, igraph_preference_game — Generates a graph with vertex types and connection preferences.
PROGRESS, IGRAPH_PROGRESS — Report progress.
progress, igraph_progress — Report progress
progressf, igraph_progressf — Report progress, printf-like version
progress_handler_stderr, igraph_progress_handler_stderr — A simple predefined progress handler.
progress_handler_t, igraph_progress_handler_t — Type of progress handler functions
pseudo_diameter, igraph_pseudo_diameter — Approximation and lower bound of diameter.
pseudo_diameter_dijkstra, igraph_pseudo_diameter_dijkstra — Approximation and lower bound of the diameter of a weighted graph.
psumtree_destroy, igraph_psumtree_destroy — Destroys a partial prefix sum tree.
psumtree_get, igraph_psumtree_get — Retrieves the value corresponding to an item in the tree.
psumtree_init, igraph_psumtree_init — Initializes a partial prefix sum tree.
psumtree_search, igraph_psumtree_search — Finds an item in the tree, given a value.
psumtree_size, igraph_psumtree_size — Returns the size of the tree.
psumtree_sum, igraph_psumtree_sum — Returns the sum of the values of the leaves in the tree.
psumtree_update, igraph_psumtree_update — Updates the value associated to an item in the tree.

R

radius, igraph_radius — Radius of a graph.
radius_dijkstra, igraph_radius_dijkstra — Radius of a graph, using weighted edges.
random_edge_walk, igraph_random_edge_walk — Performs a random walk on a graph and returns the traversed edges.
random_sample, igraph_random_sample — Generates an increasing random sequence of integers.
random_spanning_tree, igraph_random_spanning_tree — Uniformly samples the spanning trees of a graph.
random_walk, igraph_random_walk — Performs a random walk on a graph.
read_graph_dimacs, igraph_read_graph_dimacs — Read a graph in DIMACS format (deprecated alias).
read_graph_dimacs_flow, igraph_read_graph_dimacs_flow — Read a graph in DIMACS format.
read_graph_dl, igraph_read_graph_dl — Reads a file in the DL format of UCINET.
read_graph_edgelist, igraph_read_graph_edgelist — Reads an edge list from a file and creates a graph.
read_graph_gml, igraph_read_graph_gml — Read a graph in GML format.
read_graph_graphdb, igraph_read_graph_graphdb — Read a graph in the binary graph database format.
read_graph_graphml, igraph_read_graph_graphml — Reads a graph from a GraphML file.
read_graph_lgl, igraph_read_graph_lgl — Reads a graph from an .lgl file.
read_graph_ncol, igraph_read_graph_ncol — Reads an .ncol file used by LGL.
read_graph_pajek, igraph_read_graph_pajek — Reads a file in Pajek format.
realize_degree_sequence, igraph_realize_degree_sequence — Generates a graph with the given degree sequence.
realloc, igraph_realloc — Reallocate memory that can be safely deallocated by igraph functions.
recent_degree_aging_game, igraph_recent_degree_aging_game — Preferential attachment based on the number of edges gained recently, with aging of vertices.
recent_degree_game, igraph_recent_degree_game — Stochastic graph generator based on the number of incident edges a node has gained recently.
reciprocity, igraph_reciprocity — Calculates the reciprocity of a directed graph.
regular_tree, igraph_regular_tree — Creates a regular tree.
reindex_membership, igraph_reindex_membership — Makes the IDs in a membership vector contiguous.
reverse_edges, igraph_reverse_edges — Reverses some edges of a directed graph.
rewire, igraph_rewire — Randomly rewires a graph while preserving its degree sequence.
rewire_directed_edges, igraph_rewire_directed_edges — Rewires the chosen endpoint of directed edges.
rewire_edges, igraph_rewire_edges — Rewires the edges of a graph with constant probability.
ring, igraph_ring — Creates a cycle graph or a path graph.
rngtype_glibc2, igraph_rngtype_glibc2 — The random number generator introduced in GNU libc 2.
rngtype_mt19937, igraph_rngtype_mt19937 — The MT19937 random number generator.
rngtype_pcg32, igraph_rngtype_pcg32 — The PCG random number generator (32-bit version).
rngtype_pcg64, igraph_rngtype_pcg64 — The PCG random number generator (64-bit version).
rng_bits, igraph_rng_bits — The number of random bits that a random number generator can produces in a single round.
rng_default, igraph_rng_default — Query the default random number generator.
rng_destroy, igraph_rng_destroy — Deallocates memory associated with a random number generator.
rng_get_binom, igraph_rng_get_binom — Samples from a binomial distribution.
rng_get_exp, igraph_rng_get_exp — Samples from an exponential distribution.
rng_get_gamma, igraph_rng_get_gamma — Samples from a gamma distribution.
rng_get_geom, igraph_rng_get_geom — Samples from a geometric distribution.
rng_get_integer, igraph_rng_get_integer — Generate an integer random number from an interval.
rng_get_normal, igraph_rng_get_normal — Samples from a normal distribution.
rng_get_pois, igraph_rng_get_pois — Samples from a Poisson distribution.
rng_get_unif, igraph_rng_get_unif — Samples real numbers from a given interval.
rng_get_unif01, igraph_rng_get_unif01 — Samples uniformly from the unit interval.
rng_init, igraph_rng_init — Initializes a random number generator.
rng_max, igraph_rng_max — The maximum possible integer for a random number generator.
rng_name, igraph_rng_name — The type of a random number generator.
rng_seed, igraph_rng_seed — Seeds a random number generator.
rng_set_default, igraph_rng_set_default — Set the default igraph random number generator.
roots_for_tree_layout, igraph_roots_for_tree_layout — Roots suitable for a nice tree layout.
roulette_wheel_imitation, igraph_roulette_wheel_imitation — Adopt a strategy via roulette wheel selection.
running_mean, igraph_running_mean — Calculates the running mean of a vector.

S

sample_dirichlet, igraph_sample_dirichlet — Sample points from a Dirichlet distribution.
sample_sphere_surface, igraph_sample_sphere_surface — Sample points uniformly from the surface of a sphere.
sample_sphere_volume, igraph_sample_sphere_volume — Sample points uniformly from the volume of a sphere.
sbm_game, igraph_sbm_game — Sample from a stochastic block model.
SETEAB, SETEAB — Set a boolean edge attribute
SETEABV, SETEABV — Set a boolean edge attribute for all edges
SETEAN, SETEAN — Set a numeric edge attribute
SETEANV, SETEANV — Set a numeric edge attribute for all edges
SETEAS, SETEAS — Set a string edge attribute
SETEASV, SETEASV — Set a string edge attribute for all edges
SETGAB, SETGAB — Set a boolean graph attribute
SETGAN, SETGAN — Set a numeric graph attribute
SETGAS, SETGAS — Set a string graph attribute
SETVAB, SETVAB — Set a boolean vertex attribute
SETVABV, SETVABV — Set a boolean vertex attribute for all vertices
SETVAN, SETVAN — Set a numeric vertex attribute
SETVANV, SETVANV — Set a numeric vertex attribute for all vertices
SETVAS, SETVAS — Set a string vertex attribute
SETVASV, SETVASV — Set a string vertex attribute for all vertices
set_attribute_table, igraph_set_attribute_table — Attach an attribute table.
set_error_handler, igraph_set_error_handler — Sets a new error handler.
set_fatal_handler, igraph_set_fatal_handler — Installs a fatal error handler.
set_progress_handler, igraph_set_progress_handler — Install a progress handler, or remove the current handler.
set_status_handler, igraph_set_status_handler — Install of uninstall a status handler function.
set_warning_handler, igraph_set_warning_handler — Installs a warning handler.
shortest_paths, igraph_shortest_paths — Length of the shortest paths between vertices.
shortest_paths_bellman_ford, igraph_shortest_paths_bellman_ford — Weighted shortest path lengths between vertices, allowing negative weights (deprecated).
shortest_paths_dijkstra, igraph_shortest_paths_dijkstra — Weighted shortest path lengths between vertices (deprecated).
shortest_paths_johnson, igraph_shortest_paths_johnson — Weighted shortest path lengths between vertices, using Johnson's algorithm (deprecated).
similarity_dice, igraph_similarity_dice — Dice similarity coefficient.
similarity_dice_es, igraph_similarity_dice_es — Dice similarity coefficient for a given edge selector.
similarity_dice_pairs, igraph_similarity_dice_pairs — Dice similarity coefficient for given vertex pairs.
similarity_inverse_log_weighted, igraph_similarity_inverse_log_weighted — Vertex similarity based on the inverse logarithm of vertex degrees.
similarity_jaccard, igraph_similarity_jaccard — Jaccard similarity coefficient for the given vertices.
similarity_jaccard_es, igraph_similarity_jaccard_es — Jaccard similarity coefficient for a given edge selector.
similarity_jaccard_pairs, igraph_similarity_jaccard_pairs — Jaccard similarity coefficient for given vertex pairs.
simple_interconnected_islands_game, igraph_simple_interconnected_islands_game — Generates a random graph made of several interconnected islands, each island being a random graph.
simplify, igraph_simplify — Removes loop and/or multiple edges from the graph.
simplify_and_colorize, igraph_simplify_and_colorize — Simplify the graph and compute self-loop and edge multiplicities.
sir, igraph_sir — Performs a number of SIR epidemics model runs on a graph.
sir_destroy, igraph_sir_destroy — Deallocates memory associated with a SIR simulation run.
sir_t, igraph_sir_t — The result of one SIR model simulation.
small, igraph_small — Shorthand to create a small graph, giving the edges as arguments.
spanner, igraph_spanner — Calculates a spanner of a graph with a given stretch factor.
sparsemat, igraph_sparsemat — Creates an igraph graph from a sparse matrix.
sparsemat_add, igraph_sparsemat_add — Sum of two sparse matrices.
sparsemat_add_cols, igraph_sparsemat_add_cols — Adds columns to a sparse matrix.
sparsemat_add_rows, igraph_sparsemat_add_rows — Adds rows to a sparse matrix.
sparsemat_arpack_rnsolve, igraph_sparsemat_arpack_rnsolve — Eigenvalues and eigenvectors of a nonsymmetric sparse matrix via ARPACK.
sparsemat_arpack_rssolve, igraph_sparsemat_arpack_rssolve — Eigenvalues and eigenvectors of a symmetric sparse matrix via ARPACK.
sparsemat_as_matrix, igraph_sparsemat_as_matrix — Converts a sparse matrix to a dense matrix.
sparsemat_cholsol, igraph_sparsemat_cholsol — Solves a symmetric linear system via Cholesky decomposition.
sparsemat_colsums, igraph_sparsemat_colsums — Column-wise sums.
sparsemat_compress, igraph_sparsemat_compress — Converts a sparse matrix to column-compressed format.
sparsemat_copy, igraph_sparsemat_copy — Copies a sparse matrix (deprecated alias).
sparsemat_count_nonzero, igraph_sparsemat_count_nonzero — Counts nonzero elements of a sparse matrix.
sparsemat_count_nonzerotol, igraph_sparsemat_count_nonzerotol — Counts nonzero elements of a sparse matrix, ignoring elements close to zero.
sparsemat_destroy, igraph_sparsemat_destroy — Deallocates memory used by a sparse matrix.
sparsemat_diag, igraph_sparsemat_diag — Creates a sparse diagonal matrix (deprecated alias).
sparsemat_droptol, igraph_sparsemat_droptol — Drops the almost zero elements from a sparse matrix.
sparsemat_dropzeros, igraph_sparsemat_dropzeros — Drops the zero elements from a sparse matrix.
sparsemat_dupl, igraph_sparsemat_dupl — Removes duplicate elements from a sparse matrix.
sparsemat_entry, igraph_sparsemat_entry — Adds an element to a sparse matrix.
sparsemat_eye, igraph_sparsemat_eye — Creates a sparse identity matrix (deprecated alias).
sparsemat_fkeep, igraph_sparsemat_fkeep — Filters the elements of a sparse matrix.
sparsemat_gaxpy, igraph_sparsemat_gaxpy — Matrix-vector product, added to another vector.
sparsemat_get, igraph_sparsemat_get — Return the value of a single element from a sparse matrix.
sparsemat_getelements, igraph_sparsemat_getelements — Returns all elements of a sparse matrix.
sparsemat_getelements_sorted, igraph_sparsemat_getelements_sorted — Returns all elements of a sparse matrix, sorted by row and column indices.
sparsemat_index, igraph_sparsemat_index — Extracts a submatrix or a single element.
sparsemat_init, igraph_sparsemat_init — Initializes a sparse matrix, in triplet format.
sparsemat_init_copy, igraph_sparsemat_init_copy — Copies a sparse matrix.
sparsemat_init_diag, igraph_sparsemat_init_diag — Creates a sparse diagonal matrix.
sparsemat_init_eye, igraph_sparsemat_init_eye — Creates a sparse identity matrix.
sparsemat_is_cc, igraph_sparsemat_is_cc — Is this sparse matrix in column-compressed format?
sparsemat_is_symmetric, igraph_sparsemat_is_symmetric — Returns whether a sparse matrix is symmetric.
sparsemat_is_triplet, igraph_sparsemat_is_triplet — Is this sparse matrix in triplet format?
sparsemat_iterator_col, igraph_sparsemat_iterator_col — Return the column of the iterator.
sparsemat_iterator_end, igraph_sparsemat_iterator_end — Query if the iterator is past the last element.
sparsemat_iterator_get, igraph_sparsemat_iterator_get — Return the element at the current iterator position.
sparsemat_iterator_idx, igraph_sparsemat_iterator_idx — Returns the element vector index of a sparse matrix iterator.
sparsemat_iterator_init, igraph_sparsemat_iterator_init — Initialize a sparse matrix iterator.
sparsemat_iterator_next, igraph_sparsemat_iterator_next — Let a sparse matrix iterator go to the next element.
sparsemat_iterator_reset, igraph_sparsemat_iterator_reset — Reset a sparse matrix iterator to the first element.
sparsemat_iterator_row, igraph_sparsemat_iterator_row — Return the row of the iterator.
sparsemat_lsolve, igraph_sparsemat_lsolve — Solves a lower-triangular linear system.
sparsemat_ltsolve, igraph_sparsemat_ltsolve — Solves an upper-triangular linear system.
sparsemat_lu, igraph_sparsemat_lu — LU decomposition of a sparse matrix.
sparsemat_luresol, igraph_sparsemat_luresol — Solves a linear system using a precomputed LU decomposition.
sparsemat_lusol, igraph_sparsemat_lusol — Solves a linear system via LU decomposition.
sparsemat_max, igraph_sparsemat_max — Maximum of a sparse matrix.
sparsemat_min, igraph_sparsemat_min — Minimum of a sparse matrix.
sparsemat_minmax, igraph_sparsemat_minmax — Minimum and maximum of a sparse matrix.
sparsemat_multiply, igraph_sparsemat_multiply — Matrix multiplication.
sparsemat_ncol, igraph_sparsemat_ncol — Number of columns.
sparsemat_nonzero_storage, igraph_sparsemat_nonzero_storage — Returns number of stored entries of a sparse matrix.
sparsemat_nrow, igraph_sparsemat_nrow — Number of rows.
sparsemat_numeric_destroy, igraph_sparsemat_numeric_destroy — Deallocates memory after a numeric decomposition.
sparsemat_permute, igraph_sparsemat_permute — Permutes the rows and columns of a sparse matrix.
sparsemat_print, igraph_sparsemat_print — Prints a sparse matrix to a file.
sparsemat_qr, igraph_sparsemat_qr — QR decomposition of a sparse matrix.
sparsemat_qrresol, igraph_sparsemat_qrresol — Solves a linear system using a precomputed QR decomposition.
sparsemat_realloc, igraph_sparsemat_realloc — Allocates more (or less) memory for a sparse matrix.
sparsemat_resize, igraph_sparsemat_resize — Resizes a sparse matrix and clears all the elements.
sparsemat_rowsums, igraph_sparsemat_rowsums — Row-wise sums.
sparsemat_scale, igraph_sparsemat_scale — Scales a sparse matrix.
sparsemat_sort, igraph_sparsemat_sort — Sorts all elements of a sparse matrix by row and column indices.
sparsemat_symblu, igraph_sparsemat_symblu — Symbolic LU decomposition.
sparsemat_symbolic_destroy, igraph_sparsemat_symbolic_destroy — Deallocates memory after a symbolic decomposition.
sparsemat_symbqr, igraph_sparsemat_symbqr — Symbolic QR decomposition.
sparsemat_transpose, igraph_sparsemat_transpose — Transposes a sparse matrix.
sparsemat_type, igraph_sparsemat_type — Type of a sparse matrix (triplet or column-compressed).
sparsemat_usolve, igraph_sparsemat_usolve — Solves an upper-triangular linear system.
sparsemat_utsolve, igraph_sparsemat_utsolve — Solves a lower-triangular linear system.
sparsemat_view, igraph_sparsemat_view — Initialize a sparse matrix and set all parameters.
sparse_adjacency, igraph_sparse_adjacency — Creates a graph from a sparse adjacency matrix.
sparse_weighted_adjacency, igraph_sparse_weighted_adjacency — Creates a graph from a weighted sparse adjacency matrix.
split_join_distance, igraph_split_join_distance — Calculates the split-join distance of two community structures.
square_lattice, igraph_square_lattice — Arbitrary dimensional square lattices.
stack_clear, igraph_stack_clear — Removes all elements from a stack.
stack_destroy, igraph_stack_destroy — Destroys a stack object.
stack_empty, igraph_stack_empty — Decides whether a stack object is empty.
stack_init, igraph_stack_init — Initializes a stack.
stack_pop, igraph_stack_pop — Removes and returns an element from the top of a stack.
stack_push, igraph_stack_push — Places an element on the top of a stack.
stack_reserve, igraph_stack_reserve — Reserve memory.
stack_size, igraph_stack_size — Returns the number of elements in a stack.
stack_top, igraph_stack_top — Query top element.
star, igraph_star — Creates a star graph, every vertex connects only to the center.
static_fitness_game, igraph_static_fitness_game — Non-growing random graph with edge probabilities proportional to node fitness scores.
static_power_law_game, igraph_static_power_law_game — Generates a non-growing random graph with expected power-law degree distributions.
STATUS, IGRAPH_STATUS — Report the status of an igraph function.
status, igraph_status — Reports status from an igraph function.
STATUSF, IGRAPH_STATUSF — Report the status from an igraph function
statusf, igraph_statusf — Report status, more flexible printf-like version.
status_handler_stderr, igraph_status_handler_stderr — A simple predefined status handler function.
status_handler_t, igraph_status_handler_t — The type of the igraph status handler functions
stochastic_imitation, igraph_stochastic_imitation — Adopt a strategy via stochastic imitation with uniform selection.
STR, STR — Indexing string vectors.
strength, igraph_strength — Strength of the vertices, also called weighted vertex degree.
strerror, igraph_strerror — Textual description of an error.
strvector_add, igraph_strvector_add — Adds an element to the back of a string vector (deprecated alias).
strvector_append, igraph_strvector_append — Concatenates two string vectors.
strvector_capacity, igraph_strvector_capacity — Returns the capacity of a string vector.
strvector_clear, igraph_strvector_clear — Removes all elements from a string vector.
strvector_copy, igraph_strvector_copy — Initialization by copying (deprecated alias).
strvector_destroy, igraph_strvector_destroy — Frees the memory allocated for the string vector.
strvector_get, igraph_strvector_get — Retrieves an element of the string vector.
strvector_init, igraph_strvector_init — Initializes a string vector.
strvector_init_copy, igraph_strvector_init_copy — Initialization by copying.
strvector_merge, igraph_strvector_merge — Moves the contents of a string vector to the end of another.
strvector_push_back, igraph_strvector_push_back — Adds an element to the back of a string vector.
strvector_push_back_len, igraph_strvector_push_back_len — Adds a string of the given length to the back of a string vector.
strvector_remove, igraph_strvector_remove — Removes a single element from a string vector.
strvector_remove_section, igraph_strvector_remove_section — Removes a section from a string vector.
strvector_reserve, igraph_strvector_reserve — Reserves memory for a string vector.
strvector_resize, igraph_strvector_resize — Resizes a string vector.
strvector_resize_min, igraph_strvector_resize_min — Deallocates the unused memory of a string vector.
strvector_set, igraph_strvector_set — Sets an element of the string vector from a string.
strvector_set2, igraph_strvector_set2 — Sets an element of the string vector given a buffer and its size (deprecated alias).
strvector_set_len, igraph_strvector_set_len — Sets an element of the string vector given a buffer and its size.
strvector_size, igraph_strvector_size — Returns the size of a string vector.
st_edge_connectivity, igraph_st_edge_connectivity — Edge connectivity of a pair of vertices.
st_mincut, igraph_st_mincut — Minimum cut between a source and a target vertex.
st_mincut_value, igraph_st_mincut_value — The minimum s-t cut in a graph.
st_vertex_connectivity, igraph_st_vertex_connectivity — The vertex connectivity of a pair of vertices.
subcomponent, igraph_subcomponent — The vertices in the same component as a given vertex.
subgraph_edges, igraph_subgraph_edges — Creates a subgraph with the specified edges and their endpoints (deprecated alias).
subgraph_from_edges, igraph_subgraph_from_edges — Creates a subgraph with the specified edges and their endpoints.
subisomorphic, igraph_subisomorphic — Decide subgraph isomorphism.
subisomorphic_function_vf2, igraph_subisomorphic_function_vf2 — Generic VF2 function for subgraph isomorphism problems (deprecated alias).
subisomorphic_lad, igraph_subisomorphic_lad — Check subgraph isomorphism with the LAD algorithm
subisomorphic_vf2, igraph_subisomorphic_vf2 — Decide subgraph isomorphism using VF2
symmetric_tree, igraph_symmetric_tree — Creates a symmetric tree with the specified number of branches at each level.

T

THREAD_SAFE, IGRAPH_THREAD_SAFE — Specifies whether igraph was built in thread-safe mode.
TO, IGRAPH_TO — The target vertex of an edge.
topological_sorting, igraph_topological_sorting — Calculate a possible topological sorting of the graph.
to_directed, igraph_to_directed — Convert an undirected graph to a directed one.
to_prufer, igraph_to_prufer — Converts a tree to its Prüfer sequence.
to_undirected, igraph_to_undirected — Convert a directed graph to an undirected one.
transitivity_avglocal_undirected, igraph_transitivity_avglocal_undirected — Average local transitivity (clustering coefficient).
transitivity_barrat, igraph_transitivity_barrat — Weighted local transitivity of some vertices, as defined by A. Barrat.
transitivity_local_undirected, igraph_transitivity_local_undirected — The local transitivity (clustering coefficient) of some vertices.
transitivity_undirected, igraph_transitivity_undirected — Calculates the transitivity (clustering coefficient) of a graph.
tree, igraph_tree — Creates a k-ary tree in which almost all vertices have k children (deprecated alias).
tree_game, igraph_tree_game — Generates a random tree with the given number of nodes.
triad_census, igraph_triad_census — Triad census, as defined by Davis and Leinhardt.
triangular_lattice, igraph_triangular_lattice — A triangular lattice with the given shape.
trussness, igraph_trussness — Finding the "trussness" of the edges in a network.
turan, igraph_turan — Create a Turán graph.

U

unfold_tree, igraph_unfold_tree — Unfolding a graph into a tree, by possibly multiplicating its vertices.
union, igraph_union — Calculates the union of two graphs.
union_many, igraph_union_many — Creates the union of many graphs.

V

VAB, VAB — Query a boolean vertex attribute.
VABV, VABV — Query a boolean vertex attribute for all vertices.
VAN, VAN — Query a numeric vertex attribute.
VANV, VANV — Query a numeric vertex attribute for all vertices.
VAS, VAS — Query a string vertex attribute.
VASV, VASV — Query a string vertex attribute for all vertices.
vcount, igraph_vcount — The number of vertices in a graph.
VCOUNT_MAX, IGRAPH_VCOUNT_MAX — The maximum number of vertices supported in igraph graphs.
VECTOR, VECTOR — Accessing an element of a vector.
vector_add, igraph_vector_add — Add two vectors.
vector_add_constant, igraph_vector_add_constant — Add a constant to the vector.
vector_all_almost_e, igraph_vector_all_almost_e — Are all elements almost equal?
vector_all_e, igraph_vector_all_e — Are all elements equal?
vector_all_g, igraph_vector_all_g — Are all elements greater?
vector_all_ge, igraph_vector_all_ge — Are all elements greater or equal?
vector_all_l, igraph_vector_all_l — Are all elements less?
vector_all_le, igraph_vector_all_le — Are all elements less or equal?
vector_append, igraph_vector_append — Append a vector to another one.
vector_binsearch, igraph_vector_binsearch — Finds an element by binary searching a sorted vector.
vector_binsearch2, igraph_vector_binsearch2 — Binary search, without returning the index.
vector_binsearch_slice, igraph_vector_binsearch_slice — Finds an element by binary searching a sorted slice of a vector.
vector_capacity, igraph_vector_capacity — Returns the allocated capacity of the vector.
vector_clear, igraph_vector_clear — Removes all elements from a vector.
vector_colex_cmp, igraph_vector_colex_cmp — Colexicographical comparison of two vectors.
vector_colex_cmp_untyped, igraph_vector_colex_cmp_untyped — Colexicographical comparison of two vectors.
vector_complex_all_almost_e, igraph_vector_complex_all_almost_e — Are all elements almost equal?
vector_complex_create, igraph_vector_complex_create — Creates a complex vector from a real and imaginary part.
vector_complex_create_polar, igraph_vector_complex_create_polar — Creates a complex matrix from a magnitude and an angle.
vector_complex_imag, igraph_vector_complex_imag — Gives the imaginary part of a complex vector.
vector_complex_real, igraph_vector_complex_real — Gives the real part of a complex vector.
vector_complex_realimag, igraph_vector_complex_realimag — Gives the real and imaginary parts of a complex vector.
vector_complex_zapsmall, igraph_vector_complex_zapsmall — Replaces small elements of a complex vector by exact zeros.
vector_contains, igraph_vector_contains — Linear search in a vector.
vector_copy, igraph_vector_copy — Initializes a vector from another vector object (deprecated alias).
vector_copy_to, igraph_vector_copy_to — Copies the contents of a vector to a C array.
vector_destroy, igraph_vector_destroy — Destroys a vector object.
vector_difference_sorted, igraph_vector_difference_sorted — Calculates the difference between two sorted vectors (considered as sets).
vector_div, igraph_vector_div — Divide a vector by another one.
vector_e, igraph_vector_e — Access an element of a vector (deprecated alias).
vector_empty, igraph_vector_empty — Decides whether the size of the vector is zero.
vector_e_ptr, igraph_vector_e_ptr — Get the address of an element of a vector.
vector_fill, igraph_vector_fill — Fill a vector with a constant element.
vector_floor, igraph_vector_floor — Transform a real vector to an integer vector by flooring each element.
vector_get, igraph_vector_get — Access an element of a vector.
vector_get_ptr, igraph_vector_get_ptr — Get the address of an element of a vector.
vector_init, igraph_vector_init — Initializes a vector object (constructor).
vector_init_array, igraph_vector_init_array — Initializes a vector from an ordinary C array (constructor).
vector_init_copy, igraph_vector_init_copy — Initializes a vector from another vector object (constructor).
vector_init_range, igraph_vector_init_range — Initializes a vector with a range.
vector_init_seq, igraph_vector_init_seq — Initializes a vector with a sequence, inclusive endpoints (deprecated).
vector_insert, igraph_vector_insert — Inserts a single element into a vector.
vector_intersect_sorted, igraph_vector_intersect_sorted — Calculates the intersection of two sorted vectors.
vector_isininterval, igraph_vector_isininterval — Checks if all elements of a vector are in the given interval.
vector_is_any_nan, igraph_vector_is_any_nan — Check if any element is NaN.
vector_is_nan, igraph_vector_is_nan — Check for each element if it is NaN.
vector_lex_cmp, igraph_vector_lex_cmp — Lexicographical comparison of two vectors (type-safe variant).
vector_lex_cmp_untyped, igraph_vector_lex_cmp_untyped — Lexicographical comparison of two vectors (non-type-safe).
vector_list_capacity, igraph_vector_list_capacity — Returns the allocated capacity of the list.
vector_list_clear, igraph_vector_list_clear — Removes all elements from a list of vectors.
vector_list_destroy, igraph_vector_list_destroy — Destroys a list of vectors object.
vector_list_discard, igraph_vector_list_discard — Discard the item at the given index in the vector list.
vector_list_discard_back, igraph_vector_list_discard_back — Discard the last item in the vector list.
vector_list_discard_fast, igraph_vector_list_discard_fast — Discard the item at the given index in the vector list and move the last item to its place.
vector_list_empty, igraph_vector_list_empty — Decides whether the size of the list is zero.
vector_list_get_ptr, igraph_vector_list_get_ptr — Retrieve the address of a vector in the vector list.
vector_list_init, igraph_vector_list_init — Initializes a list of vectors (constructor).
vector_list_insert, igraph_vector_list_insert — Insert an existing vector into the list, transferring ownership.
vector_list_insert_copy, igraph_vector_list_insert_copy — Insert the copy of a vector to the list.
vector_list_insert_new, igraph_vector_list_insert_new — Insert a new vector into the list.
vector_list_permute, igraph_vector_list_permute — Permutes the elements of a list in place according to an index vector.
vector_list_pop_back, igraph_vector_list_pop_back — Remove the last item from the vector list and transfer ownership to the caller.
vector_list_push_back, igraph_vector_list_push_back — Append an existing vector to the list, transferring ownership.
vector_list_push_back_copy, igraph_vector_list_push_back_copy — Append the copy of a vector to the list.
vector_list_push_back_new, igraph_vector_list_push_back_new — Append a new vector to the list.
vector_list_remove, igraph_vector_list_remove — Remove the item at the given index from the vector list and transfer ownership to the caller.
vector_list_remove_fast, igraph_vector_list_remove_fast — Remove the item at the given index in the vector list, move the last item to its place and transfer ownership to the caller.
vector_list_replace, igraph_vector_list_replace — Replaces the vector at the given index in the list with another one.
vector_list_reserve, igraph_vector_list_reserve — Reserves memory for a list.
vector_list_resize, igraph_vector_list_resize — Resize the list of vectors.
vector_list_set, igraph_vector_list_set — Sets the vector at the given index in the list.
vector_list_size, igraph_vector_list_size — Returns the size (=length) of the vector.
vector_list_sort, igraph_vector_list_sort — Sorts the elements of the list into ascending order.
vector_list_sort_ind, igraph_vector_list_sort_ind — Returns a permutation of indices that sorts the list.
vector_list_swap, igraph_vector_list_swap — Swaps all elements of two vector lists.
vector_list_swap_elements, igraph_vector_list_swap_elements — Swap two elements in a vector list.
vector_list_tail_ptr, igraph_vector_list_tail_ptr — Retrieve the address of the last vector in the vector list.
vector_max, igraph_vector_max — Largest element of a vector.
vector_maxdifference, igraph_vector_maxdifference — The maximum absolute difference of m1 and m2.
vector_min, igraph_vector_min — Smallest element of a vector.
vector_minmax, igraph_vector_minmax — Minimum and maximum elements of a vector.
vector_mul, igraph_vector_mul — Multiply two vectors.
vector_null, igraph_vector_null — Sets each element in the vector to zero.
vector_permute, igraph_vector_permute — Permutes the elements of a vector in place according to an index vector.
vector_pop_back, igraph_vector_pop_back — Removes and returns the last element of a vector.
vector_prod, igraph_vector_prod — Calculates the product of the elements in the vector.
vector_ptr_clear, igraph_vector_ptr_clear — Removes all elements from a pointer vector.
vector_ptr_copy, igraph_vector_ptr_copy — Initializes a pointer vector from another one (deprecated alias).
vector_ptr_destroy, igraph_vector_ptr_destroy — Destroys a pointer vector.
vector_ptr_destroy_all, igraph_vector_ptr_destroy_all — Frees all the elements and destroys the pointer vector.
vector_ptr_e, igraph_vector_ptr_e — Access an element of a pointer vector (deprecated alias).
vector_ptr_free_all, igraph_vector_ptr_free_all — Frees all the elements of a pointer vector.
vector_ptr_get, igraph_vector_ptr_get — Access an element of a pointer vector.
vector_ptr_get_item_destructor, igraph_vector_ptr_get_item_destructor — Gets the current item destructor for this pointer vector.
vector_ptr_init, igraph_vector_ptr_init — Initialize a pointer vector (constructor).
vector_ptr_init_copy, igraph_vector_ptr_init_copy — Initializes a pointer vector from another one (constructor).
vector_ptr_insert, igraph_vector_ptr_insert — Inserts a single element into a pointer vector.
vector_ptr_permute, igraph_vector_ptr_permute — Permutes the elements of a pointer vector in place according to an index vector.
vector_ptr_pop_back, igraph_vector_ptr_pop_back — Removes and returns the last element of a pointer vector.
vector_ptr_push_back, igraph_vector_ptr_push_back — Appends an element to the back of a pointer vector.
vector_ptr_resize, igraph_vector_ptr_resize — Resizes a pointer vector.
vector_ptr_set, igraph_vector_ptr_set — Assign to an element of a pointer vector.
vector_ptr_set_item_destructor, igraph_vector_ptr_set_item_destructor — Sets the item destructor for this pointer vector.
VECTOR_PTR_SET_ITEM_DESTRUCTOR, IGRAPH_VECTOR_PTR_SET_ITEM_DESTRUCTOR — Sets the item destructor for this pointer vector (macro version).
vector_ptr_size, igraph_vector_ptr_size — Gives the number of elements in the pointer vector.
vector_ptr_sort, igraph_vector_ptr_sort — Sorts the pointer vector based on an external comparison function.
vector_ptr_sort_ind, igraph_vector_ptr_sort_ind — Returns a permutation of indices that sorts a vector of pointers.
vector_push_back, igraph_vector_push_back — Appends one element to a vector.
vector_qsort_ind, igraph_vector_qsort_ind — Returns a permutation of indices that sorts a vector.
vector_range, igraph_vector_range — Updates a vector to store a range.
vector_remove, igraph_vector_remove — Removes a single element from a vector.
vector_remove_section, igraph_vector_remove_section — Deletes a section from a vector.
vector_reserve, igraph_vector_reserve — Reserves memory for a vector.
vector_resize, igraph_vector_resize — Resize the vector.
vector_resize_min, igraph_vector_resize_min — Deallocate the unused memory of a vector.
vector_reverse, igraph_vector_reverse — Reverse the elements of a vector.
vector_reverse_sort, igraph_vector_reverse_sort — Sorts the elements of the vector into descending order.
vector_scale, igraph_vector_scale — Multiplies all elements of a vector by a constant.
vector_search, igraph_vector_search — Searches in a vector from a given position.
vector_set, igraph_vector_set — Assignment to an element of a vector.
vector_shuffle, igraph_vector_shuffle — Shuffles a vector in-place using the Fisher-Yates method.
vector_size, igraph_vector_size — Returns the size (=length) of the vector.
vector_sort, igraph_vector_sort — Sorts the elements of the vector into ascending order.
vector_sub, igraph_vector_sub — Subtract a vector from another one.
vector_sum, igraph_vector_sum — Calculates the sum of the elements in the vector.
vector_swap, igraph_vector_swap — Swap all elements of two vectors.
vector_swap_elements, igraph_vector_swap_elements — Swap two elements in a vector.
vector_tail, igraph_vector_tail — Returns the last element in a vector.
vector_update, igraph_vector_update — Update a vector from another one.
vector_view, igraph_vector_view — Handle a regular C array as a igraph_vector_t.
vector_which_max, igraph_vector_which_max — Gives the index of the maximum element of the vector.
vector_which_min, igraph_vector_which_min — Index of the smallest element.
vector_which_minmax, igraph_vector_which_minmax — Index of the minimum and maximum elements.
vector_zapsmall, igraph_vector_zapsmall — Replaces small elements of a vector by exact zeros.
version, igraph_version — The version of the igraph C library.
vertex_coloring_greedy, igraph_vertex_coloring_greedy — Computes a vertex coloring using a greedy algorithm.
vertex_connectivity, igraph_vertex_connectivity — The vertex connectivity of a graph.
vertex_disjoint_paths, igraph_vertex_disjoint_paths — Maximum number of vertex-disjoint paths between two vertices.
vertex_path_from_edge_path, igraph_vertex_path_from_edge_path — Converts a path of edge IDs to the traversed vertex IDs.
vit_create, igraph_vit_create — Creates a vertex iterator from a vertex selector.
vit_destroy, igraph_vit_destroy — Destroys a vertex iterator.
VIT_END, IGRAPH_VIT_END — Are we at the end?
VIT_GET, IGRAPH_VIT_GET — Query the current position.
VIT_NEXT, IGRAPH_VIT_NEXT — Next vertex.
VIT_RESET, IGRAPH_VIT_RESET — Reset a vertex iterator.
VIT_SIZE, IGRAPH_VIT_SIZE — Size of a vertex iterator.
voronoi, igraph_voronoi — Voronoi partitioning of a graph.
vss_1, igraph_vss_1 — Vertex set with a single vertex (immediate version).
vss_all, igraph_vss_all — All vertices of a graph (immediate version).
vss_none, igraph_vss_none — Empty vertex set (immediate version).
vss_range, igraph_vss_range — An interval of vertices (immediate version).
vss_seq, igraph_vss_seq — An interval of vertices with inclusive endpoints (immediate version, deprecated).
vss_vector, igraph_vss_vector — Vertex set based on a vector (immediate version).
vs_1, igraph_vs_1 — Vertex set with a single vertex.
vs_adj, igraph_vs_adj — Adjacent vertices of a vertex.
vs_all, igraph_vs_all — Vertex set, all vertices of a graph.
vs_copy, igraph_vs_copy — Creates a copy of a vertex selector.
vs_destroy, igraph_vs_destroy — Destroy a vertex set.
vs_is_all, igraph_vs_is_all — Check whether all vertices are included.
vs_nonadj, igraph_vs_nonadj — Non-adjacent vertices of a vertex.
vs_none, igraph_vs_none — Empty vertex set.
vs_range, igraph_vs_range — Vertex set, an interval of vertices.
vs_seq, igraph_vs_seq — Vertex set, an interval of vertices with inclusive endpoints (deprecated).
vs_size, igraph_vs_size — Returns the size of the vertex selector.
vs_type, igraph_vs_type — Returns the type of the vertex selector.
vs_vector, igraph_vs_vector — Vertex set based on a vector.
vs_vector_copy, igraph_vs_vector_copy — Vertex set based on a vector, with copying.
vs_vector_small, igraph_vs_vector_small — Create a vertex set by giving its elements.

W

WARNING, IGRAPH_WARNING — Triggers a warning.
warning, igraph_warning — Reports a warning.
WARNINGF, IGRAPH_WARNINGF — Triggers a warning, with printf-like syntax.
warningf, igraph_warningf — Reports a warning, printf-like version.
warning_handler_ignore, igraph_warning_handler_ignore — Ignores all warnings.
warning_handler_print, igraph_warning_handler_print — Prints all warnings to the standard error.
warning_handler_t, igraph_warning_handler_t — The type of igraph warning handler functions.
watts_strogatz_game, igraph_watts_strogatz_game — The Watts-Strogatz small-world model.
weighted_adjacency, igraph_weighted_adjacency — Creates a graph from a weighted adjacency matrix.
weighted_cliques, igraph_weighted_cliques — Finds all cliques in a given weight range in a vertex weighted graph.
weighted_clique_number, igraph_weighted_clique_number — Finds the weight of the largest weight clique in the graph.
wheel, igraph_wheel — Creates a wheel graph, a union of a star and a cycle graph.
widest_path_widths_dijkstra, igraph_widest_path_widths_dijkstra — Widths of widest paths between vertices.
widest_path_widths_floyd_warshall, igraph_widest_path_widths_floyd_warshall — Widths of widest paths between vertices.
write_graph_dimacs, igraph_write_graph_dimacs — Write a graph in DIMACS format (deprecated alias).
write_graph_dimacs_flow, igraph_write_graph_dimacs_flow — Write a graph in DIMACS format.
write_graph_dot, igraph_write_graph_dot — Write the graph to a stream in DOT format.
write_graph_edgelist, igraph_write_graph_edgelist — Writes the edge list of a graph to a file.
write_graph_gml, igraph_write_graph_gml — Write the graph to a stream in GML format.
write_graph_graphml, igraph_write_graph_graphml — Writes the graph to a file in GraphML format.
write_graph_leda, igraph_write_graph_leda — Write a graph in LEDA native graph format.
write_graph_lgl, igraph_write_graph_lgl — Writes the graph to a file in .lgl format.
write_graph_ncol, igraph_write_graph_ncol — Writes the graph to a file in .ncol format.
write_graph_pajek, igraph_write_graph_pajek — Writes a graph to a file in Pajek format.