15 lines
876 B
Plaintext
15 lines
876 B
Plaintext
For a given matrix, return the [[wp:Determinant|determinant]] and the [[wp:Permanent|permanent]] of the matrix.
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The determinant is given by
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:: <big><math>\det(A) = \sum_\sigma\sgn(\sigma)\prod_{i=1}^n M_{i,\sigma_i}</math></big>
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while the permanent is given by
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:: <big><math> \operatorname{perm}(A)=\sum_\sigma\prod_{i=1}^n M_{i,\sigma_i}</math></big>
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In both cases the sum is over the permutations <math>\sigma</math> of the permutations of 1, 2, ..., ''n''. (A permutation's sign is 1 if there are an even number of inversions and -1 otherwise; see [[wp:Parity of a permutation|parity of a permutation]].)
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More efficient algorithms for the determinant are known: [[LU decomposition]], see for example [[wp:LU decomposition#Computing the determinant]]. Efficient methods for calculating the permanent are not known.
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;Related task:
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* [[Permutations by swapping]]
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<br><br>
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