R: Functions to generate alternate representations of graphs

morphers {tidygraph}

R Documentation

Functions to generate alternate representations of graphs

Description

These functions are meant to be passed into morph() to create a temporary alternate representation of the input graph. They are thus not meant to be called directly. See below for detail of each morpher.

Usage

to_linegraph(graph)

to_subgraph(graph, ..., subset_by = NULL)

to_split(graph, ..., split_by = NULL)

to_components(graph, type = "weak")

to_complement(graph, loops = FALSE)

to_local_neighborhood(graph, node, order = 1, mode = "all")

to_dominator_tree(graph, root, mode = "out")

to_minimum_spanning_tree(graph, weights = NULL)

to_shortest_path(graph, from, to, mode = "out", weights = NULL)

to_bfs_tree(graph, root, mode = "out", unreachable = FALSE)

to_dfs_tree(graph, root, mode = "out", unreachable = FALSE)

to_simple(graph)

to_contracted(graph, ..., simplify = TRUE)

Arguments

`graph`	A `tbl_graph`
`...`	Arguments to pass on to `filter()` or `group_by()`
`subset_by, split_by`	Whether to create subgraphs based on nodes or edges
`type`	The type of component to split into. Either `'weak'` or `'strong'`
`loops`	Should loops be included. Defaults to `FALSE`
`node`	The center of the neighborhood
`order`	The radius of the neighborhood
`mode`	How should edges be followed? `'out'` only follows outbound edges, `'in'` only follows inbound edges, and `'all'` follows all edges. This parameter is ignored for undirected graphs.
`root`	The root of the tree
`weights`	Optional edge weights for the calculations
`from, to`	The start and end node of the path
`unreachable`	Should the search jump to a node in a new component when stuck.
`simplify`	Should edges in the contracted graph be simplified? Defaults to `TRUE`

Value

A list of tbl_graphs

Functions

to_linegraph: Convert a graph to its line graph. When unmorphing node data will be merged back into the original edge data. Edge data will be ignored.
to_subgraph: Convert a graph to a single subgraph. ... is evaluated in the same manner as filter. When unmorphing all data in the subgraph will get merged back.
to_split: Convert a graph into a list of separate subgraphs. ... is evaluated in the same manner as group_by. When unmorphing all data in the subgraphs will get merged back, but in the case of split_by = 'edges' only the first instance of node data will be used (as the same node can be present in multiple subgraphs).
to_components: Split a graph into its separate components. When unmorphing all data in the subgraphs will get merged back.
to_complement: Convert a graph into its complement. When unmorphing only node data will get merged back.
to_local_neighborhood: Convert a graph into the local neighborhood around a single node. When unmorphing all data will be merged back.
to_dominator_tree: Convert a graph into its dominator tree based on a specific root. When unmorphing only node data will get merged back.
to_minimum_spanning_tree: Convert a graph into its minimum spanning tree/forest. When unmorphing all data will get merged back.
to_shortest_path: Limit a graph to the shortest path between two nodes. When unmorphing all data is merged back.
to_bfs_tree: Convert a graph into a breath-first search tree based on a specific root. When unmorphing only node data is merged back.
to_dfs_tree: Convert a graph into a depth-first search tree based on a specific root. When unmorphing only node data is merged back.
to_simple: Collapse parallel edges and remove loops in a graph. When unmorphing all data will get merged back
to_contracted: Combine multiple nodes into one. ... is evaluated in the same manner as group_by. When unmorphing all data will get merged back.

Examples

# Compute only on a subgraph of every even node
create_notable('meredith') %>%
  morph(to_subgraph, seq_len(graph_order()) %% 2 == 0) %>%
  mutate(neighbour_count = centrality_degree()) %>%
  unmorph()

[Package tidygraph version 1.0.0 Index]