Find Instrumental Variables — Instrumental Variables • ggdag

node_instrumental tags instrumental variables given an exposure and outcome. ggdag_instrumental plots all instrumental variables. See dagitty::instrumentalVariables() for details.

Usage

node_instrumental(.dag, exposure = NULL, outcome = NULL, ...)

ggdag_instrumental(
  .tdy_dag,
  exposure = NULL,
  outcome = NULL,
  ...,
  size = 1,
  edge_type = c("link_arc", "link", "arc", "diagonal"),
  node_size = 16,
  text_size = 3.88,
  label_size = text_size,
  text_col = "white",
  label_col = "black",
  edge_width = 0.6,
  edge_cap = 10,
  arrow_length = 5,
  use_edges = TRUE,
  use_nodes = TRUE,
  use_stylized = FALSE,
  use_text = TRUE,
  use_labels = FALSE,
  text = NULL,
  label = NULL,
  node = deprecated(),
  stylized = deprecated()
)

Arguments

.dag, .tdy_dag: input graph, an object of class tidy_dagitty or dagitty
exposure: character vector of length 1, name of exposure variable. Default is NULL, in which case it will check the input DAG for exposure.
outcome: character vector of length 1, name of exposure variable. Default is NULL, in which case it will check the input DAG for exposure.
...: additional arguments passed to tidy_dagitty()
size: A numeric value scaling the size of all elements in the DAG. This allows you to change the scale of the DAG without changing the proportions.
edge_type: The type of edge, one of "link_arc", "link", "arc", "diagonal".
node_size: The size of the nodes.
text_size: The size of the text.
label_size: The size of the labels.
text_col: The color of the text.
label_col: The color of the labels.
edge_width: The width of the edges.
edge_cap: The size of edge caps (the distance between the arrowheads and the node borders).
arrow_length: The length of arrows on edges.
use_edges: A logical value. Include a geom_dag_edges*() function? If TRUE, which is determined by edge_type.
use_nodes: A logical value. Include geom_dag_point()?
use_stylized: A logical value. Include geom_dag_node()?
use_text: A logical value. Include geom_dag_text()?
use_labels: A logical value. Include geom_dag_label_repel()?
text: The bare name of a column to use for geom_dag_text(). If use_text = TRUE, the default is to use name.
label: The bare name of a column to use for geom_dag_label_repel(). If use_labels = TRUE, the default is to use label.
node: Deprecated.
stylized: Deprecated.

Value

a tidy_dagitty with an instrumental column for instrumental variables or a ggplot

Examples

library(dagitty)

node_instrumental(dagitty("dag{ i->x->y; x<->y }"), "x", "y")
#> # A DAG with 3 nodes and 3 edges
#> #
#> # A tibble: 4 × 10
#>   name        x      y direction to       xend   yend circular instrumental_name
#>   <chr>   <dbl>  <dbl> <fct>     <chr>   <dbl>  <dbl> <lgl>    <chr>            
#> 1 i      0.408   1.62  ->        x     -0.0720  0.557 FALSE    i                
#> 2 x     -0.0720  0.557 ->        y     -0.439  -0.255 FALSE    i                
#> 3 x     -0.0720  0.557 <->       y     -0.439  -0.255 FALSE    i                
#> 4 y     -0.439  -0.255 NA        NA    NA      NA     FALSE    i                
#> # ℹ 1 more variable: instrumental <chr>
ggdag_instrumental(dagitty("dag{ i->x->y; i2->x->y; x<->y }"), "x", "y")