daddto.go

package matrix

// AddTo performs: d += a * s
func (d Dense) AddTo(a Dense, s float64) {
	d.checkDim(a)
	switch s {
	case 1:
		for i := 0; i < d.numrow; i++ {
			dr := d.v[i*d.stride:]
			ar := a.v[i*a.stride:]
			k, n := 0, d.numcol-1
			for k < n {
				dr[k+0] += ar[k+0]
				dr[k+1] += ar[k+1]
				k += 2
			}
			if k == n {
				dr[k] += ar[k]
			}
		}
	case -1:
		for i := 0; i < d.numrow; i++ {
			dr := d.v[i*d.stride:]
			ar := a.v[i*a.stride:]
			k, n := 0, d.numcol-1
			for k < n {
				dr[k+0] -= ar[k+0]
				dr[k+1] -= ar[k+1]
				k += 2
			}
			if k == n {
				dr[k] -= ar[k]
			}
		}
	default:
		for i := 0; i < d.numrow; i++ {
			dr := d.v[i*d.stride:]
			ar := a.v[i*a.stride:]
			k, n := 0, d.numcol-1
			for k < n {
				dr[k+0] += ar[k+0] * s
				dr[k+1] += ar[k+1] * s
				k += 2
			}
			if k == n {
				dr[k] += ar[k] * s
			}
		}
	}
}