Creating (small) graphs via a simple interface

graph.formula() was renamed to graph_from_literal() to create a more consistent API.

Usage

graph.formula(..., simplify = TRUE)

...: For graph_from_literal() the formulae giving the structure of the graph, see details below. For from_literal() all arguments are passed to graph_from_literal().
simplify: Logical scalar, whether to call simplify() on the created graph. By default the graph is simplified, loop and multiple edges are removed. simplify() is only called when the created graph is not already simple, so the edge order from the formula is preserved whenever no loops or multi-edges are present. When the graph does contain loops or multi-edges (and simplify = TRUE), simplify() reorders the edges into its canonical order.