Approaching the problem from a slightly different angle, one can first transform a permutation vector p into a permutation matrix, for instance: julia> function MP(p) ℓ = length(p) vcat([ begin t=reshape(repeat([0], ℓ), 1, ℓ); t[i]=1; t; end for i in p ]...) end MP (gen…

[image] mikmoore: Although the permutation should be inverse-applied (i.e., with its transpose) on one side or the other if it’s actually to be treated as a permutation matrix, which would make this a bit more complicated. Yes, the getindex should be Base.getindex(P::PermutationMatrix, i::In…

Constructing a permutation matrix

General Usage

cnaak May 22, 2025, 10:47pm 11

From this article, it seems to me that the proposed implementation of @gdalle is already correct, isn’t it?

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Constructing a permutation matrix

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