Exemplo n.º 1
0
// SolveCholeskyVec finds the vector v that solves A * v = b where A is represented
// by the Cholesky decomposition, placing the result in the receiver.
func (v *Vector) SolveCholeskyVec(chol *Cholesky, b *Vector) error {
	n := chol.chol.mat.N
	vn := b.Len()
	if vn != n {
		panic(matrix.ErrShape)
	}
	v.reuseAs(n)
	if v != b {
		v.CopyVec(b)
	}
	blas64.Trsv(blas.Trans, chol.chol.mat, v.mat)
	blas64.Trsv(blas.NoTrans, chol.chol.mat, v.mat)
	if chol.cond > matrix.ConditionTolerance {
		return matrix.Condition(chol.cond)
	}
	return nil

}
Exemplo n.º 2
0
// SolveCholeskyVec finds the vector v that solves A * v = b where A = L * L^T or
// A = U^T * U, and U or L are represented by t, placing the result in the
// receiver.
func (v *Vector) SolveCholeskyVec(t Triangular, b *Vector) {
	_, n := t.Dims()
	vn := b.Len()
	if vn != n {
		panic(ErrShape)
	}
	v.reuseAs(n)
	if v != b {
		v.CopyVec(b)
	}
	ta := getBlasTriangular(t)
	switch ta.Uplo {
	case blas.Upper:
		blas64.Trsv(blas.Trans, ta, v.mat)
		blas64.Trsv(blas.NoTrans, ta, v.mat)
	case blas.Lower:
		blas64.Trsv(blas.NoTrans, ta, v.mat)
		blas64.Trsv(blas.Trans, ta, v.mat)
	default:
		panic(badTriangle)
	}
}