/*
* private Tensor GetRegion(long[] dimensionStarts, long[] dimensionSizes)
* {
* var result = this.CopyRef();
* for (int i = 0; i < dimensionStarts.Length; ++i)
* {
* var resultOld = result;
* result.Narrow(i, dimensionStarts[i], dimensionSizes[i]);
* resultOld.Dispose();
* }
* return result;
* }*/
/// <summary>
/// Copies from.
/// </summary>
/// <param name="array">The array.</param>
/// <exception cref="InvalidOperationException">
/// Tensor must be contiguous to copy from CLR array
/// or
/// Tensor and array must have the same number of elements
/// or
/// Tensor and array must have the same element types
/// </exception>
public void CopyFrom(Array array)
{
var elementType = DTypeBuilder.FromCLRType(array.GetType().GetElementType());
if (!this.IsContiguous())
{
throw new InvalidOperationException("Tensor must be contiguous to copy from CLR array");
}
if (this.ElementCount() != array.LongLength)
{
throw new InvalidOperationException("Tensor and array must have the same number of elements");
}
if (this.ElementType != elementType)
{
throw new InvalidOperationException("Tensor and array must have the same element types");
}
var handle = GCHandle.Alloc(array, GCHandleType.Pinned);
try
{
var length = Buffer.ByteLength(array);
this.Storage.CopyToStorage(this.StorageOffset, handle.AddrOfPinnedObject(), length);
}
finally
{
handle.Free();
}
}
/// <summary>
/// Froms the array.
/// </summary>
/// <param name="allocator">The allocator.</param>
/// <param name="array">The array.</param>
/// <returns>Tensor.</returns>
public static NDArray FromArray(IAllocator allocator, Array array)
{
// From the CLI spec(section 8.9.1):
// Array elements shall be laid out within the array object in row - major order
// (i.e., the elements associated with the rightmost array dimension shall be laid out contiguously from lowest to highest index).
// The actual storage allocated for each array element can include platform - specific padding.
// This is already in the order we want - and here we will (potentially incorrectly) assume that there is no
// 'platform-specific padding'. This appears to be a reasonable assumption on both CLR and Mono.
// Assuming no platform-specific padding allows us to use memcpy instead of iterating and copying each element
var elementType = DTypeBuilder.FromCLRType(array.GetType().GetElementType());
var dimSizes =
Enumerable.Range(0, array.Rank)
.Select(x => (long)array.GetLength(x))
.ToArray();
var result = new NDArray(allocator, elementType, dimSizes);
result.CopyFrom(array);
return(result);
}
