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FastLinAlg :: recursiveMinors

recursiveMinors -- uses a recursive cofactor algorithm to compute the ideal of minors of a matrix

Synopsis

Description

Given a matrix M, this computes the ideal of determinants of size n ×n submatrices. This is a recursive function. It computes the minors via cofactor. This function is currently implemented in Macaulay2, whereas the minors function uses

i1 : R = QQ[x,y];
i2 : M = random(R^{5,5,5,5,5,5}, R^7);

             6       7
o2 : Matrix R  <--- R
i3 : time I2 = recursiveMinors(4, M, Threads=>0);
     -- used 0.918201 seconds

o3 : Ideal of R
i4 : time I1 = minors(4, M, Strategy=>Cofactor);
     -- used 2.98795 seconds

o4 : Ideal of R
i5 : I1 == I2

o5 = true

Ways to use recursiveMinors :