/// <summary>
/// Repeats the NdArray along an axis.
/// </summary>
/// <param name="axis">The axis to repeat along.</param>
/// <param name="repeats">The number of repetitions.</param>
/// <param name="source">The NdArray to repeat.</param>
/// <returns>The repeated NdArray.</returns>
public static NdArray <T> Replicate(int axis, int repeats, NdArray <T> source)
{
NdArray <T> .CheckAxis(axis, source);
if (repeats < 0)
{
throw new ArgumentException("Number of repetitions cannot be negative.", "repeats");
}
// 1. insert axis of size one left to repetition axis
// 2. broadcast along the new axis to number of repetitions
// 3. reshape to result shape
var step1 = source.Reshape(List.Insert(axis, 1, source.Shape));
var step2 = NdArray <T> .BraodcastDim(axis, repeats, step1);
var step3 = step2.Reshape(List.Set(axis, repeats * source.Shape[axis], source.Shape));
return(step3);
}