# R igraph manual pages

Use this if you are using igraph from R

## The GEM layout algorithm

### Description

Place vertices on the plane using the GEM force-directed layout algorithm.

### Usage

layout_with_gem(graph, coords = NULL, maxiter = 40 * vcount(graph)^2,
temp.max = vcount(graph), temp.min = 1/10,
temp.init = sqrt(vcount(graph)))

with_gem(...)


### Arguments

 graph The input graph. Edge directions are ignored. coords If not NULL, then the starting coordinates should be given here, in a two or three column matrix, depending on the dim argument. maxiter The maximum number of iterations to perform. Updating a single vertex counts as an iteration. A reasonable default is 40 * n * n, where n is the number of vertices. The original paper suggests 4 * n * n, but this usually only works if the other parameters are set up carefully. temp.max The maximum allowed local temperature. A reasonable default is the number of vertices. temp.min The global temperature at which the algorithm terminates (even before reaching maxiter iterations). A reasonable default is 1/10. temp.init Initial local temperature of all vertices. A reasonable default is the square root of the number of vertices. ... Passed to layout_with_gem.

### Details

See the referenced paper below for the details of the algorithm.

### Value

A numeric matrix with two columns, and as many rows as the number of vertices.

### Author(s)

Gabor Csardi csardi.gabor@gmail.com

### References

Arne Frick, Andreas Ludwig, Heiko Mehldau: A Fast Adaptive Layout Algorithm for Undirected Graphs, Proc. Graph Drawing 1994, LNCS 894, pp. 388-403, 1995.

layout_with_fr, plot.igraph, tkplot

Other graph layouts: add_layout_, component_wise, layout_as_bipartite, layout_as_star, layout_as_tree, layout_in_circle, layout_nicely, layout_on_grid, layout_on_sphere, layout_randomly, layout_with_dh, layout_with_fr, layout_with_graphopt, layout_with_kk, layout_with_lgl, layout_with_mds, layout_with_sugiyama, layout_, merge_coords, norm_coords, normalize

### Examples


set.seed(42)
g <- make_ring(10)
plot(g, layout=layout_with_gem)



[Package igraph version 1.2.3 Index]