Maybe its too late, but here is a fast implementation giving the signature of the output of randperm(n)
https://github.com/jlapeyre/PermPlain.jl/blob/master/src/PermPlain.jl#L271 On Monday, February 9, 2015 at 8:41:58 PM UTC+1, Blake Johnson wrote: > > I keep writing code that needs the Levi-Civita symbol, i.e.: > > \epsilon_{ijk} = { 1 if (i,j,k) is an even permutation, -1 if (i,j,k) is > an odd permutation, otherwise 0 } > > It is used frequently in physics, so I keep expecting it to be in Julia's > stdlib, perhaps under a different name (in Mathematica, it is called > Signature[]). But, if it is there, I haven't found it yet. Is it there > and I just can't find it? >
