private static NdArray <T> DotLegacy1x2 <T>(INdArray <T> x, INdArray <T> y)
{
// x.Shape = [p]
// y.Shape = [p, n]
// retval.Shape = [n]
var p = x.Shape[0];
var n = y.Shape[1];
Guard.AssertShapeMatch(p == y.Shape[0], $"x.Shape[0] = {p}, y.Shape[0] = {y.Shape[0]}");
var rawImpl = new RawNdArrayImpl <T>(new IndexArray(n));
var buffer = rawImpl.Buffer;
for (var j = 0; j < n; ++j)
{
buffer.Span[j] = Zero <T>();
for (var k = 0; k < p; ++k)
{
buffer.Span[j] = Add(buffer.Span[j], Multiply(x[k], y[k, j]));
}
}
return(new NdArray <T>(rawImpl));
}
