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Query Node Parents

Source: R/query_functions.R
query_parents.Rd

Find parent nodes for specified variables in a DAG.

Usage

query_parents(.tdy_dag, .var = NULL)

Arguments

.tdy_dag

A tidy_dagitty or dagitty object

.var

Character vector of variables to query. If NULL, returns parents for all nodes.

Value

A tibble with columns:

  • node: The node

  • parent_set: String representation of parent nodes

  • parents: List column containing parent nodes

  • n_parents: Number of parents

Examples

library(ggdag)
dag <- dagify(
  y ~ x + z,
  x ~ w
)

query_parents(dag)
#> # A tibble: 4 × 4
#>   node  parent_set parents   n_parents
#>   <chr> <chr>      <list>        <int>
#> 1 w     NA         <chr [1]>         0
#> 2 x     {w}        <chr [1]>         1
#> 3 y     {x, z}     <chr [2]>         2
#> 4 z     NA         <chr [1]>         0
query_parents(dag, .var = "y")
#> # A tibble: 1 × 4
#>   node  parent_set parents   n_parents
#>   <chr> <chr>      <list>        <int>
#> 1 y     {x, z}     <chr [2]>         2