/// <summary>
/// For axes-formed linq, operator, calculates the partial array shape.
/// </summary>
/// <param name="sourceShape"></param>
/// <param name="axes"></param>
/// <param name="flattenIndex"></param>
/// <returns></returns>
internal static IndexOrRange[] CalculatePartialShape(
IndexArray sourceShape,
ReadOnlySpan <int> axes,
int flattenIndex)
{
var len = sourceShape.Length;
var newShape = CalculateAxesFormedShape(sourceShape, axes);
var indicesOnThis = NdArrayImpl.ToShapedIndices(newShape, flattenIndex);
var indexOrRangesOnSource = new IndexOrRange[len];
for (int i = 0, j = 0; i < len; ++i)
{
if (!axes.Contains(i))
{
indexOrRangesOnSource[i] = new Index(indicesOnThis[j], false);
++j;
}
else
{
indexOrRangesOnSource[i] = Range.Whole;
}
}
return(indexOrRangesOnSource);
}
/// <inheritdoc />
/// <summary>
/// </summary>
/// <param name="source"></param>
/// <param name="slices"> [source.Rank != slices.Length] </param>
public SliceViewNdArrayImpl(NdArrayImpl <T> source, IndexOrRange[] slices)
: base(CalculateShape(source.Shape, slices))
{
Guard.AssertIndices(source.Shape, slices);
_source = source;
_slices = new IndexOrRange[slices.Length];
Array.Copy(slices, _slices, slices.Length);
}
/// <summary>
/// Create new NdArray object.
/// </summary>
/// <param name="array"></param>
internal NdArray(Array array)
{
var shape = Enumerable
.Range(0, array.Rank)
.Select(array.GetLength)
.ToIndexArray();
var entity = new RawNdArrayImpl <T>(shape);
foreach (var(value, i) in array.Cast <T>().Select((x, i) => (x, i)))
{
entity.Buffer.Span[i] = value;
}
Entity = entity;
}
/// <inheritdoc />
public void Dispose()
{
_Entity = null !;
}
internal Enumerator(NdArray <T> owner)
{
_Entity = owner.Entity;
_Position = -1;
}
/// <summary></summary>
/// <param name="shape"></param>
internal NdArray(IndexArray shape)
{
Entity = new RawNdArrayImpl <T>(shape);
}
/// <summary>
/// Create new NdArray object with entity object.
/// </summary>
/// <param name="entity"></param>
internal NdArray(NdArrayImpl <T> entity)
{
Entity = entity;
}
internal ReshapeViewNdArrayImpl(NdArrayImpl <T> source, IndexArray shape)
: base(shape)
{
_source = source;
}