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Layout with fixed coordinates

Source: R/layout_stress.R, R/layouts.R
layout_fixed_coords.Rd

force-directed graph layout based on stress majorization with fixed coordinates for some nodes

Usage

layout_with_fixed_coords(
  g,
  coords,
  weights = NA,
  iter = 500,
  tol = 1e-04,
  mds = TRUE,
  bbox = 30
)

layout_igraph_fixed_coords(
  g,
  coords,
  weights = NA,
  iter = 500,
  tol = 1e-04,
  mds = TRUE,
  bbox = 30,
  circular
)

Arguments

g

igraph object

coords

numeric n x 2 matrix, where n is the number of nodes. values are either NA or fixed coordinates. coordinates are only calculated for the NA values.

weights

possibly a numeric vector with edge weights. If this is NULL and the graph has a weight edge attribute, then the attribute is used. If this is NA then no weights are used (even if the graph has a weight attribute). By default, weights are ignored. See details for more.

iter

number of iterations during stress optimization

tol

stopping criterion for stress optimization

mds

should an MDS layout be used as initial layout (default: TRUE)

bbox

constrain dimension of output. Only relevant to determine the placement of disconnected graphs

circular

not used

Value

matrix of xy coordinates

Details

Be careful when using weights. In most cases, the inverse of the edge weights should be used to ensure that the endpoints of an edges with higher weights are closer together (weights=1/E(g)$weight).

The layout_igraph_* function should not be used directly. It is only used as an argument for plotting with 'igraph'. 'ggraph' natively supports the layout.

See also

layout_constrained_stress

Examples

library(igraph)
set.seed(12)
g <- sample_bipartite(10, 5, "gnp", 0.5)
fxy <- cbind(c(rep(0, 10), rep(1, 5)), NA)
xy <- layout_with_fixed_coords(g, fxy)