Plot a Directed Graph Emphasizing Flow

Arranges nodes of a directed graph into three distinct columns representing sources (nodes with only outgoing edges), sinks (nodes with only incoming edges), and intermediate nodes (with both incoming and outgoing edges). The layout within the intermediate column is determined using the Fruchterman-Reingold algorithm. This visualization helps understand the overall flow structure within the graph.

Usage

plotDirectedFlow(
  g,
  source_x = 0,
  mixed_x = 1,
  sink_x = 2,
  vertical_spacing = 1,
  vertex_size = 10,
  vertex_label_cex = 0.8,
  edge_arrow_size = 0.5,
  edge_width_range = c(0.1, 0.1),
  color_edges_by_weight = FALSE,
  edge_color_low = "gray80",
  edge_color_high = "black",
  ...
)

Arguments

g

An igraph object. Must be a directed graph.

source_x

Numeric scalar. The x-coordinate for source nodes. Defaults to 0.

mixed_x

Numeric scalar. The central x-coordinate for intermediate nodes. The actual layout spans mixed_x +/- 0.4. Defaults to 1.

sink_x

Numeric scalar. The x-coordinate for sink nodes. Defaults to 2.

vertical_spacing

Numeric scalar. The maximum y-coordinate, controlling the vertical spread of the layout. Defaults to 1.

vertex_size

Numeric scalar. The size of the vertices (nodes) in the plot. Defaults to 10.

vertex_label_cex

Numeric scalar. The character expansion factor for vertex labels. Defaults to 0.8.

edge_arrow_size

Numeric scalar. The size of the arrows on the edges. Defaults to 0.5.

edge_width_range

Numeric vector of length 2. The minimum and maximum width for edges when scaled by weight. If the graph is unweighted or all weights are identical, the mean of this range is used. Defaults to c(0.1, 0.1).

color_edges_by_weight

Logical scalar. If TRUE and the graph has a 'weight' edge attribute, edges will be colored based on their weight, interpolating between edge_color_low and edge_color_high.

edge_color_low

Character string. The color for the lowest edge weight when color_edges_by_weight is TRUE. Defaults to "gray80".

edge_color_high

Character string. The color for the highest edge weight when color_edges_by_weight is TRUE. Defaults to "black".

...

Additional arguments passed to igraph.

Value

Invisibly returns NULL. This function is called for its side effect of generating a plot.