# R igraph manual pages

Use this if you are using igraph from R

## Optimal edge curvature when plotting graphs

### Description

If graphs have multiple edges, then drawing them as straight lines does not show them when plotting the graphs; they will be on top of each other. One solution is to bend the edges, with diffenent curvature, so that all of them are visible.

### Usage

curve_multiple(graph, start = 0.5)


### Arguments

 graph The input graph. start The curvature at the two extreme edges. All edges will have a curvature between -start and start, spaced equally.

### Details

curve_multiple calculates the optimal edge.curved vector for plotting a graph with multiple edges, so that all edges are visible.

### Value

A numeric vector, its length is the number of edges in the graph.

### Author(s)

Gabor Csardi csardi.gabor@gmail.com

igraph.plotting for all plotting parameters, plot.igraph, tkplot and rglplot for plotting functions.

### Examples


g <- graph( c(0,1,1,0,1,2,1,3,1,3,1,3,
2,3,2,3,2,3,2,3,0,1)+1 )

curve_multiple(g)

## Not run:
set.seed(42)
plot(g)

## End(Not run)



[Package igraph version 1.2.5 Index]