Xophmeister
Reputation
211
Top tag
Next privilege 250 Rep.
 Jul 15 comment Shuffling the columns of a matrix I'm probably being stupid (highly likely), but for example, how would the $3\times 3$ permutation matrix in my example look? I can construct matrices that permute the transposed columns together, but I can't construct one which permutes them independently (i.e., different permutations per column). Jul 14 awarded Commentator Jul 14 comment Shuffling the columns of a matrix In my currently fatigued state, it didn't occur to me that the permutation matrix applies uniformly to rows. Thus, I suppose, to get the effect I am after, I would need to break the matrix up into $N$ (column) vectors, then apply a different permutation matrix to each, then reassemble (with the appropriate transposing inbetween) Jul 14 comment Shuffling the columns of a matrix Thank you :) That just leaves me with the need for a deterministic permutation matrix generator, but that's pretty straightforward and an implementation detail! Jul 14 accepted Shuffling the columns of a matrix Jul 14 revised Shuffling the columns of a matrix added 420 characters in body Jul 14 asked Shuffling the columns of a matrix May 28 comment Does it make sense to apply the Manhattan metric to an arbitrary graph? @HagenvonEitzen Yes, I suppose it does :) I was thinking too quantitatively; hence trying to force the graph into $\mathbb{Z}^n$... If you submit your comment as an answer, I'll accept it. May 28 revised Does it make sense to apply the Manhattan metric to an arbitrary graph? edited body; edited title May 28 revised Does it make sense to apply the Manhattan metric to an arbitrary graph? added 10 characters in body May 27 asked Does it make sense to apply the Manhattan metric to an arbitrary graph? Feb 19 awarded Yearling Dec 18 awarded Nice Question Dec 19 accepted Project Euler Question 222 Oct 1 comment Basic Combinatorics/Probability Question Likewise, my thanks :) This is a nice derivation; the conceptual similarity to the binomial distribution (but with variable probabilities) makes it much more clear why this is the answer. Sep 30 awarded Editor Sep 30 revised Basic Combinatorics/Probability Question Removed the incorrect expansions Sep 29 accepted Basic Combinatorics/Probability Question Sep 29 asked Basic Combinatorics/Probability Question Aug 12 accepted Is the Laplace transform a functor?