DiagrammeR (version 0.9.0)

add_nodes_from_table: Add nodes and attributes to graph from a table

Description

Add nodes and their attributes to an existing graph object from data in a CSV file or a data frame.

Usage

add_nodes_from_table(graph, table, label_col = NULL, type_col = NULL,
  set_type = NULL, drop_cols = NULL)

Arguments

graph

a graph object of class dgr_graph.

table

either a path to a CSV file, or, a data frame object.

label_col

an option to apply a column of data in the table as label attribute values.

type_col

an option to apply a column of data in the table as type attribute values.

set_type

an optional string to apply a type attribute to all nodes created from the table records.

drop_cols

an optional character vector for dropping columns from the incoming data.

Value

a graph object of class dgr_graph.

Examples

# NOT RUN {
library(dplyr)

# Specify a path to a CSV file
path_to_csv <-
  system.file("extdata", "currencies.csv",
              package = "DiagrammeR")

# To add nodes from a CSV file, call the
# `add_nodes_from_table()` function; new node ID
# values will be created as a monotonically-
# increasing values from 1
graph_1 <-
  create_graph() %>%
  add_nodes_from_table(path_to_csv)

# View part of the graph's internal node data
# frame (ndf) using `get_node_df()`
graph_1 %>% get_node_df %>% .[, 1:5] %>% head
#>   id type label iso_4217_code curr_number
#> 1  1 <NA>  <NA>           AED         784
#> 2  2 <NA>  <NA>           AFN         971
#> 3  3 <NA>  <NA>           ALL           8
#> 4  4 <NA>  <NA>           AMD          51
#> 5  5 <NA>  <NA>           ANG         532
#> 6  6 <NA>  <NA>           AOA         973

# If you would like to assign any of the table's
# columns as `type` or `label` attributes, this can
# be done with the `type_col` and `label_col`
# arguments; to set a static `type` attribute for
# all of the table records, use `set_type`
graph_2 <-
  create_graph() %>%
  add_nodes_from_table(
    path_to_csv,
    label_col = "iso_4217_code",
    set_type = "currency")

# View part of the graph's internal ndf
graph_2 %>% get_node_df() %>% .[, 1:5] %>% head()
#>   id     type label iso_4217_code curr_number
#> 1  1 currency   AED           AED         784
#> 2  2 currency   AFN           AFN         971
#> 3  3 currency   ALL           ALL           8
#> 4  4 currency   AMD           AMD          51
#> 5  5 currency   ANG           ANG         532
#> 6  6 currency   AOA           AOA         973

# Suppose you would like to not include certain
# columns from the table in the resulting graph; you
# can use the `drop_cols` argument to choose which
# columns to not include as attributes in the graph
graph_3 <-
  create_graph() %>%
  add_nodes_from_table(
    path_to_csv,
    label_col = "iso_4217_code",
    set_type = "currency",
    drop_cols = c("exponent", "currency_name"))

# Show the node attribute names for the graph
graph_3 %>% get_node_df() %>% colnames()
#> [1] "id"  type"  "label"  "iso_4217_code"
#> [5] "curr_number"
# }

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