R: ggnet - Plot a network with ggplot2

ggnet {GGally} | R Documentation

## ggnet - Plot a network with ggplot2

### Description

Function for plotting network objects using ggplot2, now replaced by the `ggnet2` function, which provides additional control over plotting parameters. Please visit http://github.com/briatte/ggnet for the latest version of ggnet2, and https://briatte.github.io/ggnet for a vignette that contains many examples and explanations.

### Usage

    ggnet(net, mode = "fruchtermanreingold", layout.par = NULL,
      layout.exp = 0, size = 9, alpha = 1, weight = "none",
      weight.legend = NA, weight.method = weight, weight.min = NA,
      weight.max = NA, weight.cut = FALSE, group = NULL, group.legend = NA,
      node.group = group, node.color = NULL, node.alpha = alpha,
      segment.alpha = alpha, segment.color = "grey50", segment.label = NULL,
      segment.size = 0.25, arrow.size = 0, arrow.gap = 0,
      arrow.type = "closed", label = FALSE, label.nodes = label,
      label.size = size/2, label.trim = FALSE, legend.size = 9,
      legend.position = "right", names = c("", ""), quantize.weights = FALSE,
      subset.threshold = 0, top8.nodes = FALSE, trim.labels = FALSE, ...)

### Arguments

`net` | an object of class `network`, or any object that can be coerced to this class, such as an adjacency or incidence matrix, or an edge list: see edgeset.constructors and network for details. If the object is of class `igraph` and the `intergraph` package is installed, it will be used to convert the object: see `asNetwork` for details.
`mode` | a placement method from those provided in the `sna` package: see gplot.layout for details. Also accepts the names of two numeric vertex attributes of `net`, or a matrix of numeric coordinates, in which case the first two columns of the matrix are used. Defaults to the Fruchterman-Reingold force-directed algorithm.
`layout.par` | options to be passed to the placement method, as listed in gplot.layout. Defaults to `NULL`.
`layout.exp` | a multiplier to expand the horizontal axis if node labels get clipped: see expand_range for details. Defaults to `0` (no expansion).
`size` | size of the network nodes. If the nodes are weighted, their area is proportionally scaled up to the size set by `size`. Defaults to `9`.
`alpha` | a level of transparency for nodes, vertices and arrows. Defaults to `1`.
`weight` | the weighting method for the nodes, which might be a vertex attribute or a vector of size values. Also accepts `"indegree"`, `"outdegree"`, `"degree"` or `"freeman"` to size the nodes by their unweighted degree centrality (`"degree"` and `"freeman"` are equivalent): see `degree` for details. All node weights must be positive. Defaults to `"none"` (no weighting).
`weight.legend` | the name to assign to the legend created by `weight`. Defaults to `NA` (no name).
`weight.method` | see `weight`
`weight.min` | whether to subset the network to nodes with a minimum size, based on the values of `weight`. Defaults to `NA` (preserves all nodes).
`weight.max` | whether to subset the network to nodes with a maximum size, based on the values of `weight`. Defaults to `NA` (preserves all nodes).
`weight.cut` | whether to cut the size of the nodes into a certain number of quantiles. Accepts `TRUE`, which tries to cut the sizes into quartiles, or any positive numeric value, which tries to cut the sizes into that many quantiles. If the size of the nodes do not contain the specified number of distinct quantiles, the largest possible number is used. See `quantile` and `cut` for details. Defaults to `FALSE` (does nothing).
`group` | the groups of the nodes, either as a vector of values or as a vertex attribute. If set to `mode` on a bipartite network, the nodes will be grouped as `"actor"` if they belong to the primary mode and `"event"` if they belong to the secondary mode.
`group.legend` | the name to assign to the legend created by `group`.
`node.group` | see `group`
`node.color` | a vector of character strings to color the nodes with, holding as many colors as there are levels in `node.group`. Defaults to `NULL`, which will assign grayscale colors to each group.
`node.alpha` | transparency of the nodes. Inherits from `alpha`.
`segment.alpha` | the level of transparency of the edges. Defaults to `alpha`, which defaults to `1`.
`segment.color` | the color of the edges, as a color value, a vector of color values, or as an edge attribute containing color values. Defaults to `"grey50"`.
`segment.label` | the labels to plot at the middle of the edges, as a single value, a vector of values, or as an edge attribute. Defaults to `NULL` (no edge labels).
`segment.size` | the size of the edges, in points, as a single numeric value, a vector of values, or as an edge attribute. Defaults to `0.25`.
`arrow.size` | the size of the arrows for directed network edges, in points. See `arrow` for details. Defaults to `0` (no arrows).
`arrow.gap` | a setting aimed at improving the display of edge arrows by plotting slightly shorter edges. Accepts any value between `0` and `1`, where a value of `0.05` will generally achieve good results when the size of the nodes is reasonably small. Defaults to `0` (no shortening).
`arrow.type` | the type of the arrows for directed network edges. See `arrow` for details. Defaults to `"closed"`.
`label` | whether to label the nodes. If set to `TRUE`, nodes are labeled with their vertex names. If set to a vector that contains as many elements as there are nodes in `net`, nodes are labeled with these. If set to any other vector of values, the nodes are labeled only when their vertex name matches one of these values. Defaults to `FALSE` (no labels).
`label.nodes` | see `label`
`label.size` | the size of the node labels, in points, as a numeric value, a vector of numeric values, or as a vertex attribute containing numeric values. Defaults to `size / 2` (half the maximum node size), which defaults to `6`.
`label.trim` | whether to apply some trimming to the node labels. Accepts any function that can process a character vector, or a strictly positive numeric value, in which case the labels are trimmed to a fixed-length substring of that length: see `substr` for details. Defaults to `FALSE` (does nothing).
`legend.size` | the size of the legend symbols and text, in points. Defaults to `9`.
`legend.position` | the location of the plot legend(s). Accepts all `legend.position` values supported by `theme`. Defaults to `"right"`.
`names` | deprecated: see `group.legend` and `size.legend`
`quantize.weights` | deprecated: see `weight.cut`
`subset.threshold` | deprecated: see `weight.min`
`top8.nodes` | deprecated: this functionality was experimental and has been removed entirely from `ggnet`
`trim.labels` | deprecated: see `label.trim`
`...` | other arguments passed to the `geom_text` object that sets the node labels: see `geom_text` for details.

### Details

The degree centrality measures that can be produced through the `weight` argument will take the directedness of the network into account, but will be unweighted. To compute weighted network measures, see the `tnet` package by Tore Opsahl (`help("tnet", package = "tnet")`).

### Author(s)

Moritz Marbach and Francois Briatte, with help from Heike Hoffmann, Pedro Jordano and Ming-Yu Liu

### See Also

`ggnet2` in this package, `gplot` in the `sna` package, and `plot.network` in the `network` package

### Examples

    library(network)

    # random adjacency matrix
    x           <- 10
    ndyads      <- x * (x - 1)
    density     <- x / ndyads
    m           <- matrix(0, nrow = x, ncol = x)
    dimnames(m) <- list(letters[ 1:x ], letters[ 1:x ])
    m[ row(m) != col(m) ] <- runif(ndyads) < density
    m

    # random undirected network
    n <- network::network(m, directed = FALSE)
    n

    ggnet(n, label = TRUE, alpha = 1, color = "white", segment.color = "black")

    # random groups
    g <- sample(letters[ 1:3 ], 10, replace = TRUE)

    # color palette
    p <- c("a" = "steelblue", "b" = "forestgreen", "c" = "tomato")

    ggnet(n, node.group = g, node.color = p, label = TRUE, color = "white")

    # edge arrows on a directed network
    ggnet(network(m, directed = TRUE), arrow.gap = 0.05, arrow.size = 10)

[Package GGally version 1.3.2 Index]