Create a layout modifier

This is a constructor function for creating custom layout modifiers. Layout modifiers can be used with layout_() to modify how layouts are calculated or to transform the resulting coordinates.

Usage

layout_modifier(...)

Arguments

...

Named arguments that define the modifier. Must include:

id

A unique identifier string for the modifier

type

Either "pre" for pre-layout or "post" for post-layout

args

A list of arguments to pass to the apply function

apply

A function with signature function(graph, layout, modifier_args) that performs the modification

Value

An object of class igraph_layout_modifier.

See also

layout_() for using modifiers, component_wise(), normalize() for examples of built-in modifiers.

Other layout modifiers: component_wise(), normalize()

Examples

# Create a custom post-layout modifier that scales coordinates
scale_by <- function(factor) {
  layout_modifier(
    id = "scale_by",
    type = "post",
    args = list(factor = factor),
    apply = function(graph, layout, modifier_args) {
      layout * modifier_args$factor
    }
  )
}

# Use the custom modifier
g <- make_ring(10)
coords <- layout_(g, in_circle(), scale_by(2))
plot(g, layout = coords)