frcd {multigraph}

Force directed layout

Description

A function to compute the graph coordinated system with a force directed layout algorithm

Usage

frcd(net, seed = seed, maxiter, drp, scl, mov, ...)

Arguments

net

an array representing the network relations

seed

(mandatory) the seed of the initial layout (see details)

maxiter

(optional) the maximum number of iterations

...

Additional argument items

scl

(optional and experimental) numerical scalar (x and y) or vector (x, y) of the graph's scale

mov

(optional and experimental) numerical scalar (x and y) or vector (x, y) to move the graph

drp

(optional) for valued networks, drop values less than specified

Details

This function is meant as an internal routine for graph visualization with a force-directed layout procedure. However, it can be used to set the coordinate system with the coord option in functions multigraph and in bmgraph. In such case, the coordinate system of the graph starts with a random displacement of nodes where NULL in the seed argument implies an initial seed based on the computer clock watch, and the number of iterations in maxiter is 60+n.

Value

A data frame with a coordinated system with two columns representing the abscissa and the ordinate in a two-dimensional rectangular Cartesian coordinate system.

Author(s)

Antonio Rivero Ostoic

References

Fruchterman, T.M.J., & Reingold, E.M. Graph drawing by force-directed placement. Software-Practice & Experience, 21(11), 1129-1164. 1991.

See Also

multigraph, bmgraph, stsm, conc

Examples

## Create the data: two binary relations among three elements
arr <- round( replace( array(runif(18), c(3,3,2)), array(runif(18),
       c(3,3,2))>.5, 3 ) )

## Coordinates for the force directed layout with random start
coord <- frcd(arr, seed = NULL)

## Plot multigraph with customized coordinates
multigraph(arr, coord = coord)