Convert a qgraph object to cograph parameters

Extracts the network, layout, and all relevant arguments from a qgraph object and passes them to a cograph plotting engine. Reads resolved values from graphAttributes rather than raw Arguments.

Usage

from_qgraph(
  qgraph_object,
  engine = c("splot", "soplot"),
  plot = TRUE,
  weight_digits = 2,
  show_zero_edges = FALSE,
  ...
)

Arguments

qgraph_object

Return value of qgraph::qgraph()

engine

Which cograph renderer to use: "splot" or "soplot". Default: "splot".

plot

Logical. If TRUE (default), immediately plot using the chosen engine.

weight_digits

Number of decimal places to round edge weights to. Default 2. Edges that round to zero are removed unless show_zero_edges = TRUE.

show_zero_edges

Logical. If TRUE, keep edges even if their weight rounds to zero. Default: FALSE.

...

Override any extracted parameter. Use qgraph-style names (e.g., minimum) or cograph names (e.g., threshold).

Value

Invisibly, a named list of cograph parameters that can be passed to splot() or soplot().

Details

Parameter Mapping

The following qgraph parameters are automatically extracted and mapped to cograph equivalents:

Node properties:

• labels/names -> labels

• color -> node_fill

• width -> node_size (scaled by 1.3x)

• shape -> node_shape (mapped to cograph equivalents)

• border.color -> node_border_color

• border.width -> node_border_width

• label.cex -> label_size

• label.color -> label_color

Edge properties:

• labels -> edge_labels

• label.cex -> edge_label_size (scaled by 0.5x)

• lty -> edge_style (numeric to name conversion)

• curve -> curvature

• asize -> arrow_size (scaled by 0.3x)

Graph properties:

• minimum -> threshold

• maximum -> maximum

• groups -> groups

• directed -> directed

• posCol/negCol -> edge_positive_color/edge_negative_color

Pie/Donut:

• pie values -> donut_fill with donut_inner_ratio=0.8

• pieColor -> donut_color

Important Notes

• edge_color and edge_width are NOT extracted because qgraph bakes its cut-based fading into these vectors, producing near-invisible edges. cograph applies its own weight-based styling instead.

• The cut parameter is also not passed because it causes faint edges with hanging labels.

• Layout coordinates from qgraph are preserved with rescale=FALSE.

• If you override layout, rescale is automatically re-enabled.

See also

cograph for creating networks from scratch, splot and soplot for plotting engines, from_tna for tna object conversion

Examples

# Convert and plot a qgraph object
if (requireNamespace("qgraph", quietly = TRUE)) {
  library(qgraph)
  adj <- matrix(c(0, .5, .3, .5, 0, .4, .3, .4, 0), 3, 3)
  q <- qgraph(adj)
  from_qgraph(q)  # Plots with splot

  # Use soplot engine instead
  from_qgraph(q, engine = "soplot")

  # Override extracted parameters
  from_qgraph(q, node_fill = "steelblue", layout = "circle")

  # Extract parameters without plotting
  params <- from_qgraph(q, plot = FALSE)
  names(params)  # See what was extracted

  # Works with themed qgraph objects
  q_themed <- qgraph(adj, theme = "colorblind", posCol = "blue")
  from_qgraph(q_themed)
}