TensorProduct is bottleneck

[itsubaki]

[itsubaki]

q/pkg/math/matrix/matrix.go

Lines 300 to 319 in 74c1226

	func (m Matrix) TensorProduct(n Matrix) Matrix {
	p, q := m.Dimension()
	a, b := n.Dimension()
	out := make(Matrix, 0, p*a)
	for i := 0; i < p; i++ {
	for k := 0; k < a; k++ {
	r := make([]complex128, 0, q*b)
	for j := 0; j < q; j++ {
	for l := 0; l < b; l++ {
	r = append(r, m[i][j]*n[k][l])
	}
	}
	out = append(out, r)
	}
	}
	return out
	}