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 = ggdag_option("node_size", 16),
  text_size = ggdag_option("text_size", 3.88),
  label_size = ggdag_option("label_size", text_size),
  text_col = ggdag_option("text_col", "white"),
  label_col = ggdag_option("label_col", "black"),
  edge_width = ggdag_option("edge_width", 0.6),
  edge_cap = ggdag_option_proportional("edge_cap", 8, 10),
  arrow_length = ggdag_option("arrow_length", 5),
  use_edges = ggdag_option("use_edges", TRUE),
  use_nodes = ggdag_option("use_nodes", TRUE),
  use_stylized = ggdag_option("use_stylized", FALSE),
  use_text = ggdag_option("use_text", TRUE),
  use_labels = ggdag_option("use_labels", FALSE),
  label_geom = ggdag_option("label_geom", geom_dag_label_repel),
  unified_legend = TRUE,
  text = NULL,
  label = NULL,
  node = deprecated(),
  stylized = deprecated()
)

Arguments

.dag: A tidy_dagitty or dagitty object
exposure: A character vector, the exposure variable. Default is NULL, in which case it will be determined from the DAG.
outcome: A character vector, the outcome variable. Default is NULL, in which case it will be determined from the DAG.
...: additional arguments passed to tidy_dagitty()
.tdy_dag: A tidy_dagitty or dagitty object
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 a label geom? The specific geom used is controlled by label_geom.
label_geom: A geom function to use for drawing labels when use_labels = TRUE. Default is geom_dag_label_repel. Other options include geom_dag_label, geom_dag_text_repel, geom_dag_label_repel2, and geom_dag_text_repel2.
unified_legend: A logical value. When TRUE and both use_edges and use_nodes are TRUE, creates a unified legend entry showing both nodes and edges in a single key, and hides the separate edge legend. This creates cleaner, more compact legends. Default is TRUE.
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 labels. 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")
#> # DAG:
#> # A `dagitty` DAG with: 3 nodes and 3 edges
#> #
#> # Data:
#> # A tibble: 4 × 9
#>   name        x         y direction to       xend      yend instrumental_name
#>   <chr>   <dbl>     <dbl> <fct>     <chr>   <dbl>     <dbl> <chr>            
#> 1 i     -1.07    2.18e-12 ->        x      0.0887 -2.66e-12 i                
#> 2 x      0.0887 -2.66e-12 ->        y      0.985   4.78e-13 i                
#> 3 x      0.0887 -2.66e-12 <->       y      0.985   4.78e-13 i                
#> 4 y      0.985   4.78e-13 NA        NA    NA      NA        i                
#> # ℹ 1 more variable: instrumental <chr>
#> #
#> # ℹ Use `pull_dag() (`?pull_dag`)` to retrieve the DAG object and `pull_dag_data() (`?pull_dag_data`)` for the data frame
ggdag_instrumental(dagitty("dag{ i->x->y; i2->x->y; x<->y }"), "x", "y")