plot_semnet {corpustools}

Visualize a semnet network

Description

plot_semnet is a wrapper for the plot.igraph() function optimized for plotting a semantic network of the "semnet" class.

Usage

plot_semnet(
  g,
  weight_attr = "weight",
  min_weight = NA,
  delete_isolates = F,
  vertexsize_attr = "freq",
  vertexsize_coef = 1,
  vertexcolor_attr = NA,
  edgewidth_coef = 1,
  max_backbone_alpha = NA,
  labelsize_coef = 1,
  labelspace_coef = 1.1,
  reduce_labeloverlap = F,
  redo_layout = F,
  return_graph = T,
  vertex.label.dist = 0.25,
  layout_fun = igraph::layout_with_fr,
  ...
)

Arguments

g

A network in the igraph format. Specifically designed for the output of coOccurenceNetwork() and windowedCoOccurenceNetwork()

weight_attr

The name of the weight attribute. Default is 'weight'

min_weight

The minimum weight. All edges with a lower weight are dropped

delete_isolates

If TRUE, isolate vertices (also after applying min_weight) are dropped

vertexsize_attr

a character string indicating a vertex attribute that represents size. Default is 'freq', which is created in the coOccurenceNetwork functions to indicate the number of times a token occured.

vertexsize_coef

a coefficient for changing the vertex size.

vertexcolor_attr

a character string indicating a vertex attribute that represents color. The attribute can also be a numeric value (e.g., a cluster membership) in which case colors are assigned to numbers. If no (valid) color attribute is given, vertex color are based on undirected fastgreedy.community() clustering.

edgewidth_coef

a coefficient for changing the edge width

max_backbone_alpha

If g has an edge attribute named alpha (added if backbone extraction is used), this specifies the maximum alpha value.

labelsize_coef

a coefficient for increasing or decreasing the size of the vertexlabel.

labelspace_coef

a coefficient that roughly determines the minimal distance between vertex labels, based on the size of labels. Only used if reduce_labeloverlap is TRUE.

reduce_labeloverlap

if TRUE, an algorithm is used to reduce overlap as best as possible.

redo_layout

If TRUE, a new layout will be calculated using layout_with_fr(). If g does not have a layout attribute (g$layout), a new layout is automatically calculated.

return_graph

if TRUE, plot_semnet() also returns the graph object with the attributes and layout as shown in the plot.

vertex.label.dist

The distance of the label to the center of the vertex

layout_fun

The igraph layout function that is used.

...

additional arguments are passed on to plot.igraph()

Details

Before plotting the network, the set_network_attributes() function is used to set pretty defaults for plotting. Optionally, reduce_labeloverlap can be used to prevent labeloverlap (as much as possible).

Value

Plots a network, and returns the network object if return_graph is TRUE.

Examples

tc = create_tcorpus(sotu_texts, doc_column = 'id')
tc$preprocess('token','feature', remove_stopwords = TRUE, use_stemming = TRUE, min_docfreq=10)

g = semnet_window(tc, 'feature', window.size = 10)
g = backbone_filter(g, max_vertices = 100)
plot_semnet(g)