func (t GeneralCols) From(a General) {
	if t.Rows != a.Rows || t.Cols != a.Cols {
		panic("blas64: mismatched dimension")
	}
	if len(t.Data) < (t.Cols-1)*t.Stride+t.Rows {
		panic("blas64: short data slice")
	}
	for i := 0; i < a.Rows; i++ {
		for j, v := range a.Data[i*a.Stride : i*a.Stride+a.Cols] {
			t.Data[i+j*t.Stride] = v
		}
	}
}
From fills the receiver with elements from a. The receiver
must have the same dimensions as a and have adequate backing
data storage.
package blas64
import "gonum.org/v1/gonum/blas"
type GeneralCols General