internal static Tensor Permute(Tensor inTensor, int[] permutations) // TODO: unify Permute() arguments
{
var padPermutationsToBarracudaRank = TensorShape.MaxRank - permutations.Length;
if (padPermutationsToBarracudaRank > 0)
{
permutations = permutations.Concat(Enumerable.Range(permutations.Length, padPermutationsToBarracudaRank)).ToArray();
}
Debug.Assert(permutations.Length == TensorShape.MaxRank);
// See: https://stackoverflow.com/a/32034565
Profiler.BeginSample("ONNXTensor.Permute");
var outTensor = new Tensor(ONNXLayout.Permute(inTensor.shape.ToArray(), permutations));
Debug.Assert(outTensor.length == inTensor.length);
// {0, 2, 3, 1} => {0, 3, 1, 2}
// {2, 3, 1, 0} => {3, 2, 0, 1}
// => {find_index(0), find_index(1), find_index(2), find_index(3)}
var reversePermute = new int[permutations.Length];
for (var i = 0; i < permutations.Length; ++i)
{
reversePermute[i] = Array.IndexOf(permutations, i);
}
// outTensor strides
var tempOutStrides = new int[TensorShape.MaxRank + 1];
tempOutStrides[8] = 1;
for (int i = 7; i >= 0; --i)
{
tempOutStrides[i] = tempOutStrides[i + 1] * outTensor.shape[i];
}
var outStride = new int[reversePermute.Length];
for (var i = 0; i < reversePermute.Length; ++i)
{
outStride[i] = tempOutStrides[reversePermute[i] + 1];
}
// inTensor strides
var inStrides = new int[TensorShape.MaxRank];
inStrides[7] = 1;
for (int i = 6; i >= 0; --i)
{
inStrides[i] = inStrides[i + 1] * inTensor.shape[i + 1];
}
for (var it = new TensorIterator(inTensor.shape); it.IsValid(); ++it)
{
outTensor[it.d0 * outStride[0] + it.d1 * outStride[1] + it.d2 * outStride[2] + it.d3 * outStride[3] + it.d4 * outStride[4] + it.d5 * outStride[5] + it.d6 * outStride[6] + it.d7 * outStride[7]] = inTensor[
it.d0 * inStrides[0] + it.d1 * inStrides[1] + it.d2 * inStrides[2] + it.d3 * inStrides[3] + it.d4 * inStrides[4] + it.d5 * inStrides[5] + it.d6 * inStrides[6] + it.d7 * inStrides[7]];
}
Profiler.EndSample();
return(outTensor);
}
public ONNXTensor NonZero()
{
//https://github.com/onnx/onnx/blob/master/docs/Operators.md#NonZero
//https://numpy.org/doc/stable/reference/generated/numpy.nonzero.html
//Return the indices of the elements that are non-zero. Iterating row major c style.
// pad with 1s to visit all elements at least once in the loop.
int[] paddedONNXShape = new int[] { 1, 1, 1, 1, 1, 1, 1, 1 };
for (int d = 0; d < rank; ++d)
{
paddedONNXShape[d] = shape[d];
}
// collect all non zero item
List <int[]> nonZeroIndices = new List <int[]>();
for (var it = new TensorIterator(m_Data.shape); it.IsValid(); it.Next())
{
if (Math.Abs(m_Data[it.index]) > Single.Epsilon)
{
nonZeroIndices.Add(new int[] { it.d0, it.d1, it.d2, it.d3, it.d4, it.d5, it.d6, it.d7 });
}
}
// store indices in dest tensor
Tensor result = new Tensor(new TensorShape(rank, nonZeroIndices.Count));
for (int i = 0; i < nonZeroIndices.Count; ++i)
{
for (int d = 0; d < rank; ++d)
{
result[d, i] = nonZeroIndices[i][d];
}
}
return(new ONNXTensor(result, new int[] { rank, nonZeroIndices.Count }));
}