floydAlgo: Compute length of shortest path between each pair of points.
In MiloMonnier/supplynet: Supply network design and robustness assessment tools

Description Usage Arguments Value Examples

Based on floyd function. If the graph is sparse, floyd seems to use the Johnson algorithm rather than more complex Floyd-Warhall algorithm. C++ code difficult to understand: https://github.com/cran/Rfast/blob/master/src/floyd_john.cpp. Adpated to Directed Acyclic graph, Floyd-Warshall algorithm is used to apply transitive closures.

1	floydAlgo(x)

`x`	An igraph object or a matrix. Matrix values represent the edges cost values. If igraph object, it is automatically converted to adjacency matrix.

A matrix m where he elements denote the length of the shortest path between each pair of points. m[i, j] is zero it means there is not any path from i to j, or a cost of 0.

library(igraph)
set.seed(123)
g = make_tree(5)
plot(g)
## Make a graph transitive closure with FW algo
m = floydAlgo(g)
m[m>1] = 1 # To adjacency matrix
g_closed = graph_from_adjacency_matrix(m)
plot(g_closed)