1
vote
0answers
78 views

How to sequentially select, from a large set of tuples (of matrices), those with a certain property

I'm interested in finding a computationally efficient way for selecting all tuples of matrices which have a certain property. The property I'm interested in is that I want the column sum, of f[the ...
0
votes
0answers
51 views

Identify columns of a huge matrix just polynomially many rows chosen at random

I am interested in the following problem in combinatorics $\Cap$ Probability. Let $\lambda \in \mathbb{N}$ be a parameter. Consider a matrix of $2^\lambda$ rows and $2^\lambda$ columns. Each column ...
4
votes
4answers
341 views

Listing matrices up to symmetry

I am interested in the equivalence relation on N x N binary matrices, in which two matrices are equivalent if one can be obtained by rotating/reflecting the other. I would like to obtain a list ...
2
votes
1answer
100 views

PermuteSubgraph not working? (Combinatorica)

I am trying to write a code to perform the QAP partialling analysis (here's a paper to know more) but the part in which I "scramble" the graph with PermuteSubgraph does nothing, I am actually not ...
3
votes
3answers
187 views

Need Help Writing (a Pascal) Matrix in Mathematica

I want to write a function $f[n]$ in Mathematica which gives me an $n\times n$ lower triangular Pascal matrix with a row of zeros in between each nonzero row. That is, I want the matrices ...
4
votes
2answers
548 views

Exact cover solution

Is it possible to get a exact cover solution(s) and/or number of possible solutions in Mathematica?
15
votes
5answers
608 views

How do I generate the upper triangular indices from a list?

I have some list {1,2,3}. How do I generate nested pairs such that I get {{1,2},{1,3},{2,3}}? That is I'd like a way to ...
8
votes
1answer
743 views

How to apply a permutation to a symmetric square matrix?

Given a symmetric square matrix, how can I apply a permutation to the rows and columns (i.e. the same permutation to both the rows and the columns) such a way that the new structure of the matrix ...