node_angle: Get the angle of nodes and edges

In ggraph: An Implementation of Grammar of Graphics for Graphs and Networks

Get the angle of nodes and edges

Description

These helper functions makes it easy to calculate the angle associated with nodes and edges. For nodes the angle is defined as the angle of the vector pointing towards the node position, and is thus mainly suited for circular layouts where it can be used to calculate the angle of labels. For edges it is simply the angle of the vector describing the edge.

Usage

node_angle(x, y, degrees = TRUE, avoid_flip = TRUE)

edge_angle(x, y, xend, yend, degrees = TRUE, avoid_flip = TRUE)

Arguments

x, y	A vector of positions
degrees	Logical. Should the angle be returned in degree (TRUE) or radians (FALSE). Defaults to TRUE.
avoid_flip	Logical. Should the angle be adjusted so that text is always upside-down
xend, yend	The end position of the edge

Value

A vector with the angle of each node/edge

Examples

require(tidygraph)
flareGraph <- tbl_graph(flare$vertices, flare$edges)

ggraph(flareGraph, 'dendrogram', circular = TRUE) +
  geom_edge_diagonal0() +
  geom_node_text(aes(filter = leaf, angle = node_angle(x, y), label = shortName),
    hjust = 'outward', size = 2
  ) +
  expand_limits(x = c(-1.3, 1.3), y = c(-1.3, 1.3))

ggraph documentation built on May 29, 2024, 2:32 a.m.