DiagrammeR (version 0.8.4)

join_node_attrs: Join new node attribute values using a data frame

Description

Join new node attribute values in a left join using a data frame. The use of a left join in this function allows for no possibility that nodes in the graph might be removed after the join.

Usage

join_node_attrs(graph, df, by_graph = NULL, by_df = NULL)

Arguments

graph

a graph object of class

df

the data frame to use for joining.

by_graph

optional specification of the column in the graph's internal node data frame for the left join. If both by_graph and by_df are not provided, then a natural join will occur if there are columns in the graph's ndf and in df with identical names.

by_df

optional specification of the column in df for the left join. If both by_graph and by_df are not provided, then a natural join will occur if there are columns in the graph's ndf and in df with identical names. dgr_graph that is created using create_graph.

Value

a graph object of class dgr_graph.

Examples

library(magrittr)

# Create a simple graph
graph <-
  create_graph() %>%
  add_n_nodes(5) %>%
  add_edges_w_string("1->2 1->3 2->4 2->5 3->5")

# Create a data frame with node ID values and a
# set of numeric values
df <- data.frame(nodes = 1:6, values = rnorm(6, 5))

# Join the values in the data frame to the
# graph's nodes; this works as a left join using
# identically-named columns in the graph and the df
# (in this case `nodes` is common to both)
graph <-
  graph %>% join_node_attrs(df)

# Get the graph's internal ndf to show that the
# join has been made
get_node_df(graph)
#>   nodes type label           values
#> 1     1            4.27988818205506
#> 2     2             5.3499594040959
#> 3     3            5.43965531750004
#> 4     4            3.50233363164518
#> 5     5            5.04599475422798