private static void AssignFromSeq(IEnumerable <Object> seq, ndarray result,
int dim, long offset)
{
if (dim >= result.ndim)
{
throw new RuntimeException(String.Format("Source dimensions ({0}) exceeded target array dimensions ({1}).", dim, result.ndim));
}
if (seq is ndarray && seq.GetType() != typeof(ndarray))
{
// Convert to an array to ensure the dimensionality reduction
// assumption works.
ndarray array = NpyCoreApi.FromArray((ndarray)seq, null, NPYARRAYFLAGS.NPY_ENSUREARRAY);
seq = (IEnumerable <object>)array;
}
if (seq.Count() != result.Dim(dim))
{
throw new RuntimeException("AssignFromSeq: sequence/array shape mismatch.");
}
long stride = result.Stride(dim);
if (dim < result.ndim - 1)
{
// Sequence elements should be additional sequences
seq.Iteri((o, i) =>
AssignFromSeq((IEnumerable <Object>)o, result, dim + 1, offset + stride * i));
}
else
{
seq.Iteri((o, i) => result.Dtype.f.setitem(offset + i * stride, o, result.Array));
}
}
/// <summary>
/// Finds the offset for a single item assignment to the array.
/// </summary>
/// <param name="arr">The array we are assigning to.</param>
/// <returns>The offset or -1 if this is not a single assignment.</returns>
internal npy_intp SingleAssignOffset(ndarray arr)
{
// Check to see that there are just newaxis, ellipsis, intp or bool indexes
for (int i = 0; i < num_indexes; i++)
{
switch (IndexType(i))
{
case NpyIndexType.NPY_INDEX_NEWAXIS:
case NpyIndexType.NPY_INDEX_ELLIPSIS:
case NpyIndexType.NPY_INDEX_INTP:
case NpyIndexType.NPY_INDEX_BOOL:
break;
default:
return(-1);
}
}
// Bind to the array and calculate the offset.
NpyIndexes bound = Bind(arr);
{
npy_intp offset = 0;
int nd = 0;
for (int i = 0; i < bound.num_indexes; i++)
{
switch (bound.IndexType(i))
{
case NpyIndexType.NPY_INDEX_NEWAXIS:
break;
case NpyIndexType.NPY_INDEX_INTP:
offset += arr.Stride(nd++) * bound.GetIntP(i);
break;
case NpyIndexType.NPY_INDEX_SLICE:
// An ellipsis became a slice on binding.
// This is not a single item assignment.
return(-1);
default:
// This should never happen
return(-1);
}
}
if (nd != arr.ndim)
{
// Not enough indexes. This is not a single item.
return(-1);
}
return(offset);
}
}
internal static ndarray PrependOnes(ndarray arr, int nd, int ndmin)
{
npy_intp[] newdims = new npy_intp[ndmin];
npy_intp[] newstrides = new npy_intp[ndmin];
int num = ndmin - nd;
// Set the first num dims and strides for the 1's
for (int i = 0; i < num; i++)
{
newdims[i] = (npy_intp)1;
newstrides[i] = (npy_intp)arr.ItemSize;
}
// Copy in the rest of dims and strides
for (int i = num; i < ndmin; i++)
{
int k = i - num;
newdims[i] = (npy_intp)arr.Dim(k);
newstrides[i] = (npy_intp)arr.Stride(k);
}
return(NpyCoreApi.NewView(arr.Dtype, ndmin, newdims, newstrides, arr, 0, false));
}