set_node_position {DiagrammeR}R Documentation

Apply a layout position to a single node

Description

Apply position information for a single node. This is done by setting the x and y attrs for a node id or node label supplied in node. When rendering the graph, nodes with attribute values set for x and y will be fixed to those positions on the graph canvas.

Usage

set_node_position(graph, node, x, y, use_labels = FALSE)

Arguments

graph

a graph object of class dgr_graph.

node

a single-length vector containing either a node ID value (integer) or a node label (character) for which position information should be applied.

x

the x coordinate to set for the node.

y

the y coordinate to set for the node.

use_labels

an option to use a node label value in node. Note that this is only possible if all nodes have distinct label values set and none exist as an NA value.

Value

a graph object of class dgr_graph.

Examples

# Create a simple graph with 4 nodes
graph <-
  create_graph() %>%
  add_node(label = "one") %>%
  add_node(label = "two") %>%
  add_node(label = "three") %>%
  add_node(label = "four")

# Add position information to each of
# the graph's nodes
graph <-
  graph %>%
  set_node_position(
    node = 1,
    x = 1, y = 1) %>%
  set_node_position(
    node = 2,
    x = 2, y = 2) %>%
  set_node_position(
    node = 3,
    x = 3, y = 3) %>%
  set_node_position(
    node = 4,
    x = 4, y = 4)

# View the graph's node data frame to
# verify that the `x` and `y` node
# attributes are available and set to
# the values provided
graph %>%
  get_node_df()

# The same function can modify the data
# in the `x` and `y` attributes
graph <-
  graph %>%
  set_node_position(
    node = 1,
    x = 1, y = 4) %>%
  set_node_position(
    node = 2,
    x = 3, y = 3) %>%
  set_node_position(
    node = 3,
    x = 3, y = 2) %>%
  set_node_position(
    node = 4,
    x = 4, y = 1)

# View the graph's node data frame
graph %>%
  get_node_df()

# Position changes can also be made by
# supplying a node `label` value (and setting
# `use_labels` to TRUE). For this to work,
# all `label` values in the graph's ndf must
# be unique and non-NA
graph <-
  graph %>%
  set_node_position(
    node = "one",
    x = 1, y = 1,
    use_labels = TRUE) %>%
  set_node_position(
    node = "two",
    x = 2, y = 2,
    use_labels = TRUE)

# View the graph's node data frame
graph %>%
  get_node_df()
[Package DiagrammeR version 1.0.1 Index]