xLayout {Pi} | R Documentation

## Function to define graph node coordinates according to igraph- or sna-style layout

### Description

`xLayout` is supposed to define graph node coordinates according to igraph- or sna-style layout.

### Usage

    xLayout(
    g,
    layout = c("layout_nicely", "layout_randomly", "layout_in_circle",
    "layout_on_sphere", "layout_with_fr", "layout_with_kk",
    "layout_as_tree",
    "layout_with_lgl", "layout_with_graphopt", "layout_with_sugiyama",
    "layout_with_dh",
    "layout_with_drl", "layout_with_gem", "layout_with_mds",
    "layout_as_bipartite",
    "gplot.layout.adj", "gplot.layout.circle", "gplot.layout.circrand",
    "gplot.layout.eigen", "gplot.layout.fruchtermanreingold",
    "gplot.layout.geodist",
    "gplot.layout.hall", "gplot.layout.kamadakawai", "gplot.layout.mds",
    "gplot.layout.princoord", "gplot.layout.random", "gplot.layout.rmds",
    "gplot.layout.segeo", "gplot.layout.seham", "gplot.layout.spring",
    "gplot.layout.springrepulse", "gplot.layout.target",
    "graphlayouts.layout_with_stress", "graphlayouts.layout_as_backbone",
    "gephi.forceatlas2"),
    seed = 825,
    flip = F
    )

### Arguments

`g` | an object of class "igraph" (or "graphNEL") for a graph
`layout` | a character specifying graph layout function. This character can be used to indicate igraph-style layout ("layout_nicely","layout_randomly","layout_in_circle","layout_on_sphere","layout_with_fr","layout_with_kk","layout_as_tree","layout_with_lgl","layout_with_graphopt","layout_with_sugiyama","layout_with_dh","layout_with_drl","layout_with_gem","layout_with_mds","layout_as_bipartite"), or sna-style layout ("gplot.layout.adj","gplot.layout.circle","gplot.layout.circrand","gplot.layout.eigen","gplot.layout.fruchtermanreingold","gplot.layout.geodist","gplot.layout.hall","gplot.layout.kamadakawai","gplot.layout.mds","gplot.layout.princoord","gplot.layout.random","gplot.layout.rmds","gplot.layout.segeo","gplot.layout.seham","gplot.layout.spring","gplot.layout.springrepulse","gplot.layout.target"), or graphlayouts-style layout ("graphlayouts.layout_with_stress","graphlayouts.layout_as_backbone"), or ForeceAtlas2 layout used in Dephi ("gephi.forceatlas2")
`seed` | an integer specifying the seed
`flip` | logical to indicate whether x- and y-coordiates flip. By default, it sets to false

### Value

It returns an igraph object, appended by node attributes including "xcoord" for x-coordinates, "ycoord" for y-coordiates.

### See Also

`xGGnetwork`

### Examples

    ## Not run:
    # Load the library
    library(XGR)
    RData.location <- "http://galahad.well.ox.ac.uk/bigdata/"

    # load REACTOME
    # restricted to Immune System ('R-HSA-168256') or Signal Transduction ('R-HSA-162582')
    g <- xRDataLoader('ig.REACTOME', RData.location=RData.location)
    neighs.out <- igraph::neighborhood(g, order=vcount(g),
    nodes="R-HSA-168256", mode="out")
    nodeInduced <- V(g)[unique(unlist(neighs.out))]$name
    ig <- igraph::induced.subgraph(g, vids=nodeInduced)

    # compare Fruchterman and Reingold force-directed placement algorithm
    ## based on igraph layout
    ig1 <- xLayout(ig, layout="layout_with_fr")
    gp1 <- xGGnetwork(ig1, node.xcoord="xcoord", node.ycoord="ycoord")
    ## based on sna layout
    ig2 <- xLayout(ig, layout="gplot.layout.fruchtermanreingold")
    gp2 <- xGGnetwork(ig2, node.xcoord="xcoord", node.ycoord="ycoord")

    # compare Kamada-Kawai force-directed placement algorithm
    ## based on igraph layout
    ig1 <- xLayout(ig, layout="layout_with_kk")
    gp1 <- xGGnetwork(ig1, node.xcoord="xcoord", node.ycoord="ycoord")
    ## based on sna layout
    ig2 <- xLayout(ig, layout="gplot.layout.kamadakawai")
    gp2 <- xGGnetwork(ig2, node.xcoord="xcoord", node.ycoord="ycoord")
    ## do together
    layouts <-
    c("layout_with_fr","gplot.layout.fruchtermanreingold","layout_with_kk","gplot.layout.kamadakawai",
    "gephi.forceatlas2")
    ls_ig <- lapply(layouts, function(x) xLayout(ig, layout=x))
    names(ls_ig) <- layouts
    gp <- xGGnetwork(ls_ig, node.xcoord='xcoord', node.ycoord='ycoord',
    ncolumns=5)

    ## End(Not run)

[Package Pi version 2.4.0 Index]