func (A *Matrix) ScaleBLAS(v float64) {
// Normal matrices.
if A.stride == A.width {
blas.Dscal(len(A.data), v, A.data, 1)
return
}
// Submatrices.
for i := 0; i < A.height; i++ {
blas.Dscal(A.width, v, A.Row(i), 1)
}
}
// MVMul multiplies a matrix with a vector
// y = alpha*A*x + y
func MVMul(N, m, n int, alpha float64, A, x, y []float64) {
if N != n {
panic("vec: Dimensions invalid. A.Cols() != Vec.Len()")
}
if alpha == 0 {
return
}
if alpha == 1 {
goto alg
}
blas.Dscal(N, alpha, A, 1)
goto alg
alg:
{
if N < 8 {
idx, ptr := 0, 0
extra := n - n%4
ub := ((n / 4) * 4) - 1
for i := 0; i < m; i++ {
idx = i * n
for j := 0; j < ub; j += 4 {
ptr = idx + j
y[i] += A[ptr]*x[j] + A[ptr+1]*x[j+1] + A[ptr+2]*x[j+2] + A[ptr+3]*x[j+3]
}
for j := extra; j < n; j++ {
y[i] += A[idx+j] * x[j]
}
}
return
}
for i := 0; i < m; i++ {
y[i] += blas.Ddot(N, A[n*i:n*i+n], 1, x, 1)
}
}
}
// Scale multiples vector, x with scalar alpha
func Scale(n int, alpha float64, x []float64) {
if n == 3 {
x[0] *= alpha
x[1] *= alpha
x[2] *= alpha
} else if n == 4 {
x[0] *= alpha
x[1] *= alpha
x[2] *= alpha
x[3] *= alpha
} else if n == 6 {
x[0] *= alpha
x[1] *= alpha
x[2] *= alpha
x[3] *= alpha
x[4] *= alpha
x[5] *= alpha
} else {
blas.Dscal(n, alpha, x, 1)
}
}
func Outer(N, m, n int, alpha float64, A, x, y []float64) {
if N != n {
panic("vec: Dimensions invalid. A.Cols() != x.Len()")
}
if alpha == 0 {
return
}
if alpha == 1 {
goto alg
}
blas.Dscal(N, alpha, x, 1)
goto alg
alg:
{
for i := 0; i < m; i++ {
blas.Daxpy(N, x[i], y, 1, A[n*i:n*i+n], 1)
}
}
}
func scal64(alpha float64, X []float64) {
blas.Dscal(len(X), alpha, X, 1)
}