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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?