Obtain all shortest paths with dynamic contextual constraints

Source: R/paths.R

All pairs shortest paths using Dijkstra's algorithm taking into account contextual constraints. Enforcement of constraints is the task of the given user-defined function.

all_pairs_shortest_paths_ctx(g, decision_fct)

Arguments

g

A nctx graph
decision_fct

The function enforcing constraints. The signature of the function is (int, int, int) -> bool, i.e. the function expects three vertex IDs for the start, the current, and the next vertex. It must evaluate to bool.

Value

A matrix describing the shortest path distances between all pairs of nodes

Details

This is basically a wrapper for shortest_path_ctx - see corresponding documentation for more details and the description of decision_fct

See also

shortest_path_ctx

Examples

library(RUnit)
suppressMessages(library(igraph))
suppressMessages(library(nctx))
file <- system.file("extdata", "bcde.directed.graphml", package="nctx")
g_i <- read_graph(file, "graphml")

dists <- distances(g_i,mode="out",weights=NA)

g <- copy_from_igraph(g_i)

checker <- function(start, cur, nxt){
TRUE
}
dists_unaltered <- nctx::all_pairs_shortest_paths_ctx(g, checker)
checkEquals(as.numeric(dists_unaltered), as.numeric(dists))

#> [1] TRUE