Questions tagged [permutation]
For questions about the functionality related to permutations in Mathematica.
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Counting automorphisms that preserve a group action
Note: the math, I believe, is not the problem here. The issue is not that I get the wrong answer, just that my code does not terminate. So, if you do not feel comfortable with the problem below, I do ...
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60
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How to iterate over Orbit of PermutationGroup?
Another day, another permutation group question.
I'm given a g=PermutationGroup[...], and a list l={1, 3, 3, 2, ...}. I know I ...
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Sum over multiindex
I would like to calculate a sum over some multi-indices, that follow a specific pattern.
$$\sum\limits_{1\le i_1<i_2<...<i_k\le N} A(k,i_1, i_2, ..., i_k).$$
$A$ is a fix expression of the ...
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Differences in AbsoluteTiming for similar codes
Consider the two following codes with the same SeedRandom (which ensures the same set of random numbers) but different use of the ...
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Any command for group products?
Is there any Mathematica command or well known technique to take the direct product between two symmetric/permutation groups?
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Find Max Instance Over Permutations
I would like to find the maximum of some objective function over all possible permutations
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75
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Custom Table, for iterating over permutations
It is common that I iterate over all permutations of 1,2...,n, either by making a table or performing a sum.
Instead of creating the set of all permutations, it would be better to iterate over them.
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Fast way to apply permutations in large list?
I have one Polynomial in the form of FF[x1,x2,x3,x4,x5,x6,x7,x8], where xi pick numbers from ...
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Sum over cyclic permutation of indices
To define the Schouten bracket I need to be able to sum over a cyclic permutation of the indices:
$$ [\Phi,\Xi]_S=\mathfrak S_{i,j,k} \left(\Phi^{is}\partial_s\Xi^{jk}+ \Xi^{is}\partial_s\Phi^{jk}\...
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Permute using symmetric vs alternating groups
Why does this happen?
Permute[{0, 0, 0}, SymmetricGroup[3]]
(* {{0, 0, 0}} *)
Permute[{0, 0, 0}, AlternatingGroup[3]]
(* {{0, 0, 0}, {0, 0, 0}, {0, 0, 0}} *)
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Efficient submatrix swaps for large sparse matrix
I am implementing the 'swap' algorithm for a binary matrix to generate matrix permutations that maintain row and column totals. My problem is that my matrices are large and sparse (e.g., 19774 x 942, ...
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Put together all possible combinations of a set of functions, variables, and operators
Using a set of functions, variables, and operators, I'm trying to assemble all of the possible combinations starting with the shortest combination and ending with the longest combination. For example, ...
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80
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How can I shuffle the indices of certain variables?
I am recursively defining rational expressions in two sets of variables $x_i$ and $y_i$. Specifically, for $m<n$, I am interested in replacing all degree-$m$ monomials of the following form: $$\...
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How to rename the output in operations?
The problem is the following, i have 23 Cycles, every cycle have a name:
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