Convert to igraph — as.igraph • networkformat

S3 methods for converting tree-based model objects into igraph graph objects. Each method calls edgelist and nodelist internally and handles column reconciliation so you get a ready-to-use graph. These methods are registered against the as.igraph generic from igraph via delayed S3 registration and are available whenever igraph is loaded.

Usage

# S3 method for class 'tree'
as.igraph(x, ...)

# S3 method for class 'randomForest'
as.igraph(x, treenum = NULL, ...)

# S3 method for class 'rpart'
as.igraph(x, ...)

# S3 method for class 'xgb.Booster'
as.igraph(x, treenum = NULL, ...)

# S3 method for class 'gbm'
as.igraph(x, treenum = NULL, ...)

Arguments

x: An object to convert (tree, randomForest, rpart, xgb.Booster, or gbm).
...: Additional arguments passed to methods.
treenum: Integer vector of tree numbers to extract. Default NULL returns all trees combined into one graph with disconnected components. Pass a single integer (e.g. 1) to extract one tree.

Value

An igraph object. For randomForest with multiple trees, the graph contains disconnected components (one per tree) and a treenum vertex/edge attribute.

Examples

if (requireNamespace("rpart", quietly = TRUE) &&
    requireNamespace("igraph", quietly = TRUE)) {
  fit <- rpart::rpart(Sepal.Length ~ ., data = iris)
  g <- igraph::as.igraph(fit)
  igraph::vcount(g)
  igraph::ecount(g)
}
#> [1] 12