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Tidy a dagitty object

Usage

tidy_dagitty(
  .dagitty,
  seed = NULL,
  layout = "nicely",
  ...,
  use_existing_coords = TRUE
)

Arguments

.dagitty

a dagitty

seed

a numeric seed for reproducible layout generation

layout

a layout available in ggraph. See ggraph::create_layout() for details. Alternatively, "time_ordered" will use time_ordered_coords() to algorithmically sort the graph by time.

...

optional arguments passed to ggraph::create_layout()

use_existing_coords

(Advanced). Logical. Use the coordinates produced by dagitty::coordinates(.dagitty)? If the coordinates are empty, tidy_dagitty() will generate a layout. Generally, setting this to FALSE is thus only useful when there is a difference in the variables coordinates and the variables in the DAG, as sometimes happens when recompiling a DAG.

Value

a tidy_dagitty object

Examples

library(dagitty)
library(ggplot2)

dag <- dagitty("dag {
  Y <- X <- Z1 <- V -> Z2 -> Y
  Z1 <- W1 <-> W2 -> Z2
  X <- W1 -> Y
  X <- W2 -> Y
  X [exposure]
  Y [outcome]
  }")

tidy_dagitty(dag)
#> # A DAG with 7 nodes and 12 edges
#> #
#> # Exposure: X
#> # Outcome: Y
#> #
#> # A tibble: 13 × 7
#>    name       x     y direction to      xend   yend
#>    <chr>  <dbl> <dbl> <fct>     <chr>  <dbl>  <dbl>
#>  1 V      1.05  0.436 ->        Z1    -0.309  0.831
#>  2 V      1.05  0.436 ->        Z2     1.44   1.80 
#>  3 W1    -0.258 1.82  ->        X     -0.665  2.29 
#>  4 W1    -0.258 1.82  ->        Y      0.563  2.27 
#>  5 W1    -0.258 1.82  ->        Z1    -0.309  0.831
#>  6 W1    -0.258 1.82  <->       W2     0.372  2.86 
#>  7 W2     0.372 2.86  ->        X     -0.665  2.29 
#>  8 W2     0.372 2.86  ->        Y      0.563  2.27 
#>  9 W2     0.372 2.86  ->        Z2     1.44   1.80 
#> 10 X     -0.665 2.29  ->        Y      0.563  2.27 
#> 11 Y      0.563 2.27  NA        NA    NA     NA    
#> 12 Z1    -0.309 0.831 ->        X     -0.665  2.29 
#> 13 Z2     1.44  1.80  ->        Y      0.563  2.27 

tidy_dagitty(dag, layout = "fr") |>
  ggplot(aes(x = x, y = y, xend = xend, yend = yend)) +
  geom_dag_node() +
  geom_dag_text() +
  geom_dag_edges() +
  theme_dag()