R igraph manual pages

Parameters for the igraph package

Description

igraph has some parameters which (usually) affect the behavior of many functions. These can be set for the whole session via igraph_options.

Usage

igraph_options(...)

igraph_opt(x, default = NULL)

Arguments

...	A list may be given as the only argument, or any number of arguments may be in the name=value form, or no argument at all may be given. See the Value and Details sections for explanation.
x	A character string holding an option name.
default	If the specified option is not set in the options list, this value is returned. This facilitates retrieving an option and checking whether it is set and setting it separately if not.

Details

The parameter values set via a call to the igraph_options function will remain in effect for the rest of the session, affecting the subsequent behaviour of the other functions of the igraph package for which the given parameters are relevant.

This offers the possibility of customizing the functioning of the igraph package, for instance by insertions of appropriate calls to igraph_options in a load hook for package igraph.

The currently used parameters in alphabetical order:

add.params

Logical scalar, whether to add model parameter to the graphs that are created by the various graph constructors. By default it is TRUE.

add.vertex.names

Logical scalar, whether to add vertex names to node level indices, like degree, betweenness scores, etc. By default it is TRUE.

annotate.plot

Logical scalar, whether to annotate igraph plots with the graph's name (name graph attribute, if present) as main, and with the number of vertices and edges as xlab. Defaults to FALSE.

dend.plot.type

The plotting function to use when plotting community structure dendrograms via plot_dendrogram

. Possible values are ‘auto’ (the default), ‘phylo’, ‘hclust’ and ‘dendrogram’. See plot_dendrogram for details.

edge.attr.comb

Specifies what to do with the edge attributes if the graph is modified. The default value is list(weight="sum", name="concat", "ignore"). See attribute.combination for details on this.

nexus.url

The base URL of the default Nexus server. See nexus for details.

print.edge.attributes

Logical constant, whether to print edge attributes when printing graphs. Defaults to FALSE.

print.full

Logical scalar, whether print.igraph should show the graph structure as well, or only a summary of the graph.

print.graph.attributes

Logical constant, whether to print graph attributes when printing graphs. Defaults to FALSE.

print.vertex.attributes

Logical constant, whether to print vertex attributes when printing graphs. Defaults to FALSE.

return.vs.es

Whether functions that return a set or sequence of vertices/edges should return formal vertex/edge sequence objects. This option was introduced in igraph version 1.0.0 and defaults to TRUE. If your package requires the old behavior, you can set it to FALSE in the .onLoad function of your package, without affecting other packages.

sparsematrices

Whether to use the Matrix package for (sparse) matrices. It is recommended, if the user works with larger graphs.

verbose

Logical constant, whether igraph functions should talk more than minimal. Eg. if TRUE thne some functions will use progress bars while computing. Defaults to FALSE.

vertex.attr.comb

Specifies what to do with the vertex attributes if the graph is modified. The default value is list(name="concat", "ignore") See attribute.combination for details on this.

Value

igraph_options returns a list with the old values of the updated parameters, invisibly. Without any arguments, it returns the values of all options.

For igraph_opt, the current value set for option x, or NULL if the option is unset.

Author(s)

Gabor Csardi csardi.gabor@gmail.com

See Also

igraph_options is similar to options and igraph_opt is similar to getOption.

Other igraph options: with_igraph_opt()

Examples

oldval <- igraph_opt("verbose")
igraph_options(verbose = TRUE)
layout_with_kk(make_ring(10))
igraph_options(verbose = oldval)

oldval <- igraph_options(verbose = TRUE, sparsematrices = FALSE)
make_ring(10)[]
igraph_options(oldval)
igraph_opt("verbose")

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