Given a matrix $M$, this computes the ideal of determinants of size $n \times n$ submatrices. The recursiveMinors function uses a recursive strategy, keeping track of the smaller minors computed so far, unlike the built-in Cofactor strategy for minors
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 1.19021 seconds o3 : Ideal of R |
i4 : time I1 = minors(4, M, Strategy=>Cofactor); -- used 3.90007 seconds o4 : Ideal of R |
i5 : I1 == I2 o5 = true |
The object recursiveMinors is a method function with options.