R: The Kamada-Kawai layout algorithm

layout_with_kk {igraph} | R Documentation

## The Kamada-Kawai layout algorithm

### Description

Place the vertices on the plane, or in the 3d space, based on a phyisical model of springs.

### Usage

    layout_with_kk(graph, coords = NULL, dim = 2, maxiter = 50 *
      vcount(graph), epsilon = 0, kkconst = vcount(graph),
      weights = NULL, minx = NULL, maxx = NULL, miny = NULL,
      maxy = NULL, minz = NULL, maxz = NULL, niter, sigma, initemp,
      coolexp, start)

    with_kk(...)

### 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.
`dim` | Integer scalar, 2 or 3, the dimension of the layout. Two dimensional layouts are places on a plane, three dimensional ones in the 3d space.
`maxiter` | The maximum number of iterations to perform. The algorithm might terminate earlier, see the `epsilon` argument.
`epsilon` | Numeric scalar, the algorithm terminates, if the maximal delta is less than this. (See the reference below for what delta means.) If you set this to zero, then the function always performs `maxiter` iterations.
`kkconst` | Numeric scalar, the Kamada-Kawai vertex attraction constant. Typical (and default) value is the number of vertices.
`weights` | Edge weights, larger values will result longer edges. Note that this is opposite to `layout_with_fr`.
`minx` | If not `NULL`, then it must be a numeric vector that gives lower boundaries for the ‘x’ coordinates of the vertices. The length of the vector must match the number of vertices in the graph.
`maxx` | Similar to `minx`, but gives the upper boundaries.
`miny` | Similar to `minx`, but gives the lower boundaries of the ‘y’ coordinates.
`maxy` | Similar to `minx`, but gives the upper boundaries of the ‘y’ coordinates.
`minz` | Similar to `minx`, but gives the lower boundaries of the ‘z’ coordinates.
`maxz` | Similar to `minx`, but gives the upper boundaries of the ‘z’ coordinates.
`niter, sigma, initemp, coolexp` | These arguments are not supported from igraph version 0.8.0 and are ignored (with a warning).
`start` | Deprecated synonym for `coords`, for compatibility.
`...` | Passed to `layout_with_kk`.

### Details

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

This function was rewritten from scratch in igraph version 0.8.0 and it follows truthfully the original publication by Kamada and Kawai now.

### Value

A numeric matrix with two (dim=2) or three (dim=3) columns, and as many rows as the number of vertices, the x, y and potentially z coordinates of the vertices.

### Author(s)

Gabor Csardi csardi.gabor@gmail.com

### References

Kamada, T. and Kawai, S.: An Algorithm for Drawing General Undirected Graphs. Information Processing Letters, 31/1, 7–15, 1989.

### See Also

`layout_with_drl`, `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_gem`, `layout_with_graphopt`, `layout_with_lgl`, `layout_with_mds`, `layout_with_sugiyama`, `layout_`, `merge_coords`, `norm_coords`, `normalize`

### Examples

    g <- make_ring(10)
    E(g)$weight <- rep(1:2, length.out=ecount(g))
    plot(g, layout=layout_with_kk, edge.label=E(g)$weight)

[Package igraph version 1.2.4.1 Index]