create_subgraph_ws {DiagrammeR} | R Documentation

## Create a subgraph using node/edge selection

### Description

Create a subgraph based on a selection of nodes or edges stored in the graph object. Selections of nodes can be performed using the following `select_...` functions: `select_nodes()`, `select_last_nodes_created()`, `select_nodes_by_degree()`, `select_nodes_by_id()`, or `select_nodes_in_neighborhood()`. Alternatively, selections of edges can be made with these functions: `select_edges()`, `select_last_edge()`, or `select_edges_by_node_id()`. Selections of nodes or edges can also be performed using any of the traversal functions (`trav_...`).

### Usage

    create_subgraph_ws(graph)

### Arguments

`graph` | a graph object of class `dgr_graph` that is created using `create_graph`.

### Value

a graph object of class `dgr_graph`.

### Examples

    # Create a node data frame (ndf)
    ndf <-
      create_node_df(
        n = 6,
        value =
          c(3.5, 2.6, 9.4,
            2.7, 5.2, 2.1))

    # Create an edge data frame (edf)
    edf <-
      create_edge_df(
        from = c(1, 2, 4, 5, 2, 6),
          to = c(2, 4, 1, 3, 5, 5))

    # Create a graph
    graph <-
      create_graph(
        nodes_df = ndf,
        edges_df = edf)

    # Create a selection of nodes, this selects
    # nodes `1`, `3`, and `5`
    graph <-
      graph %>%
      select_nodes(
        conditions = value > 3)

    # Create a subgraph based on the selection
    subgraph <- create_subgraph_ws(graph)

    # Display the graph's node data frame
    get_node_df(subgraph)
    #>   id type label value
    #> 1  1 <NA>  <NA>   3.5
    #> 2  3 <NA>  <NA>   9.4
    #> 3  5 <NA>  <NA>   5.2

    # Display the graph's edge data frame
    get_edge_df(subgraph)
    #>   id from to  rel
    #> 1  4    5  3 <NA>

[Package DiagrammeR version 0.9.2 Index]