Using Laplacians to find fiedler values

New to Julia
1

@danspielman I am trying to find the fiedler value for a directed graph using fiedler command in Laplacians package in Julia.

using LightGraphs
using Laplacians

g=watts_strogatz(100,12,0.0,is_directed=true)
a=adjacency_matrix(g)
l=fiedler(a; nev=1, tol=0.0)

However, I get the following error:

ERROR: InexactError: Int64(0.8333333333333334)
2

It seems that the fiedler function requires a matrix of Floats.
You could construct one instead writing
a = Float64.(adjacency_matrix(g))

1 Like
3

that’s worth submitting a PR for :).

If any other issues come up we should see how they are computing the laplacian.

4

Not necessarily the most related, but my brain is completely dead. Can the Laplacians package be used to solve the Laplace/Poisson equations (i.e. Poisson's equation - Wikipedia) or is that an entirely different beast?