# node_count: Get count of all nodes or certain types of nodes In DiagrammeR: Graph/Network Visualization

## Description

From a graph object of class dgr_graph, get a count of nodes in the graph and optionally obtain a count of nodes by their type.

## Usage

 1 node_count(graph, type = FALSE) 

## Arguments

 graph a graph object of class dgr_graph. type either a logical value, where TRUE provides a named vector of node count by type and FALSE (the default) provides a total count, or, a character vector of type values to filter the node count.

## Value

a numeric vector of single length.

## Examples

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 # Set a seed set.seed(23) # Create a node data frame (ndf) ndf <- create_node_df( n = 26, label = TRUE, type = c(rep("a", 7), rep("b", 9), rep("c", 8), rep("d", 2))) # Create an edge data frame (edf) edf <- create_edge_df( from = sample(1:26, replace = TRUE), to = sample(1:26, replace = TRUE), rel = c(rep("rel_a", 7), rep("rel_b", 9), rep("rel_c", 8), rep("rel_d", 2))) # Create a graph using the ndf and edf graph <- create_graph( nodes_df = ndf, edges_df = edf) # Get counts of nodes grouped by the # type attribute node_count(graph, type = TRUE) #> a b c d #> 7 9 8 2 # Get a total count of nodes with no grouping node_count(graph, type = FALSE) #> [1] 26 # Get a count of nodes of a specified type node_count(graph, type = "a") #> [1] 7 # Get a count of nodes of 2 different types node_count(graph, type = c("a", "c")) #> [1] 15 

DiagrammeR documentation built on Sept. 7, 2017, 1:06 a.m.