implement dpnp.tensordot

dpnp/dpnp_iface_linearalgebra.py

@@ -39,6 +39,7 @@
 
 
 import numpy
+from numpy.core.numeric import normalize_axis_tuple
 
 import dpnp
 from dpnp.dpnp_algo import *
@@ -404,42 +405,152 @@ def outer(x1, x2, out=None):
     return call_origin(numpy.outer, x1, x2, out=out)
 
 
-def tensordot(x1, x2, axes=2):
-    """
+def tensordot(a, b, axes=2):
+    r"""
     Compute tensor dot product along specified axes.
 
     For full documentation refer to :obj:`numpy.tensordot`.
 
-    Limitations
-    -----------
-    Parameters `x1` and `x2` are supported as :obj:`dpnp.ndarray`.
-    Keyword argument `kwargs` is currently unsupported.
-    Parameter `axes` is supported only with value ``1``.
-    Otherwise the functions will be executed sequentially on CPU.
-    Input array data types are limited by supported DPNP :ref:`Data types`.
+    Parameters
+    ----------
+    a : {dpnp_array, usm_ndarray, scalar}
+        First input array. Both inputs `a` and `b` can not be scalars at the same time.
+    b : {dpnp_array, usm_ndarray, scalar}
+        Second input array. Both inputs `a` and `b` can not be scalars at the same time.
+    axes : int or (2,) array_like
+        * integer_like
+          If an int `N`, sum over the last `N` axes of `a` and the first `N` axes
+          of `b` in order. The sizes of the corresponding axes must match.
+        * (2,) array_like
+          Or, a list of axes to be summed over, first sequence applying to `a`,
+          second to `b`. Both elements array_like must be of the same length.
+
+    Returns
+    -------
+    out : dpnp.ndarray
+        Returns the tensordot product of `a` and `b`.
 
     See Also
     --------
     :obj:`dpnp.dot` : Returns the dot product.
     :obj:`dpnp.einsum` : Evaluates the Einstein summation convention on the operands.
 
+    Notes
+    -----
+    Three common use cases are:
+        * ``axes = 0`` : tensor product :math:`a\\otimes b`
+        * ``axes = 1`` : tensor dot product :math:`a\\cdot b`
+        * ``axes = 2`` : (default) tensor double contraction :math:`a:b`
+
+    When `axes` is integer, the sequence for evaluation will be: first
+    the -Nth axis in `a` and 0th axis in `b`, and the -1th axis in `a` and
+    Nth axis in `b` last.
+
+    When there is more than one axis to sum over - and they are not the last
+    (first) axes of `a` (`b`) - the argument `axes` should consist of
+    two sequences of the same length, with the first axis to sum over given
+    first in both sequences, the second axis second, and so forth.
+
+    The shape of the result consists of the non-contracted axes of the
+    first tensor, followed by the non-contracted axes of the second.
+
     Examples
     --------
     >>> import dpnp as np
     >>> a = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
     >>> b = np.array([1, 2, 3])
-    >>> result = np.tensordot(a, b, 1)
-    >>> [x for x in result]
-    [14, 32, 50]
+    >>> np.tensordot(a, b, 1)
+    array([14, 32, 50])
+
+    >>> a = np.arange(60.).reshape(3,4,5)
+    >>> b = np.arange(24.).reshape(4,3,2)
+    >>> c = np.tensordot(a,b, axes=([1,0],[0,1]))
+    >>> c.shape
+    (5, 2)
+    >>> c
+    array([[4400., 4730.],
+           [4532., 4874.],
+           [4664., 5018.],
+           [4796., 5162.],
+           [4928., 5306.]])
+
+    A slower but equivalent way of computing the same...
+
+    >>> d = np.zeros((5,2))
+    >>> for i in range(5):
+    ...   for j in range(2):
+    ...     for k in range(3):
+    ...       for n in range(4):
+    ...         d[i,j] += a[k,n,i] * b[n,k,j]
+    >>> c == d
+    array([[ True,  True],
+           [ True,  True],
+           [ True,  True],
+           [ True,  True],
+           [ True,  True]])
 
     """
 
-    x1_desc = dpnp.get_dpnp_descriptor(x1, copy_when_nondefault_queue=False)
-    x2_desc = dpnp.get_dpnp_descriptor(x2, copy_when_nondefault_queue=False)
-    if x1_desc and x2_desc and (axes == 1):
-        return dpnp_tensordot_not_implemented(x1_desc, x2_desc)  # dpnp_matmul
+    dpnp.check_supported_arrays_type(a, b, scalar_type=True)
 
-    return call_origin(numpy.tensordot, x1, x2, axes)
+    if dpnp.isscalar(a):
+        a = dpnp.array(a, sycl_queue=b.sycl_queue, usm_type=b.usm_type)
+    elif dpnp.isscalar(b):
+        b = dpnp.array(b, sycl_queue=a.sycl_queue, usm_type=a.usm_type)
+
+    try:
+        iter(axes)
+    except Exception:
+        if not isinstance(axes, int):
+            raise ValueError("Axes must be an integer.")
+        axes_a = tuple(range(-axes, 0))
+        axes_b = tuple(range(0, axes))
+    else:
+        if len(axes) != 2:
+            raise ValueError("Axes must consist of two sequences.")
+
+        axes_a, axes_b = axes
+        axes_a = (axes_a,) if dpnp.isscalar(axes_a) else axes_a
+        axes_b = (axes_b,) if dpnp.isscalar(axes_b) else axes_b
+
+        if len(axes_a) != len(axes_b):
+            raise ValueError("Axes length mismatch.")
+
+    a_shape = a.shape
+    b_shape = b.shape
+    for axis_a, axis_b in zip(axes_a, axes_b):
+        if a_shape[axis_a] != b_shape[axis_b]:
+            raise ValueError(
+                "shape of input arrays is not similar at requested axes."
+            )
+
+    # Make the axes non-negative
+    a_ndim = a.ndim
+    b_ndim = b.ndim
+    axes_a = normalize_axis_tuple(axes_a, a_ndim, "axis")
+    axes_b = normalize_axis_tuple(axes_b, b_ndim, "axis")
+
+    # Move the axes to sum over, to the end of "a"
+    notin = tuple(k for k in range(a_ndim) if k not in axes_a)
+    newaxes_a = notin + axes_a
+    N1 = int(numpy.prod([a_shape[ax] for ax in notin]))
+    N2 = int(numpy.prod([a_shape[ax] for ax in axes_a]))
+    newshape_a = (N1, N2)
+    olda = [a_shape[axis] for axis in notin]
+
+    # Move the axes to sum over, to the front of "b"
+    notin = tuple(k for k in range(b_ndim) if k not in axes_b)
+    newaxes_b = tuple(axes_b + notin)
+    N1 = int(numpy.prod([b_shape[ax] for ax in axes_b]))
+    N2 = int(numpy.prod([b_shape[ax] for ax in notin]))
+    newshape_b = (N1, N2)
+    oldb = [b_shape[axis] for axis in notin]
+
+    at = a.transpose(newaxes_a).reshape(newshape_a)
+    bt = b.transpose(newaxes_b).reshape(newshape_b)
+    res = dpnp.matmul(at, bt)
+
+    return res.reshape(olda + oldb)
 
 
 def vdot(a, b):

dpnp/dpnp_iface_sorting.py

@@ -1,5 +1,3 @@
-# cython: language_level=3
-# distutils: language = c++
 # -*- coding: utf-8 -*-
 # *****************************************************************************
 # Copyright (c) 2016-2024, Intel Corporation

tests/skipped_tests.tbl

@@ -335,10 +335,6 @@ tests/third_party/cupy/linalg_tests/test_einsum.py::TestListArgEinSumError::test
 tests/third_party/cupy/linalg_tests/test_product.py::TestMatrixPower::test_matrix_power_invlarge
 tests/third_party/cupy/linalg_tests/test_product.py::TestMatrixPower::test_matrix_power_large
 tests/third_party/cupy/linalg_tests/test_product.py::TestMatrixPower::test_matrix_power_of_two
-tests/third_party/cupy/linalg_tests/test_product.py::TestProduct::test_tensordot_zero_dim
-tests/third_party/cupy/linalg_tests/test_product.py::TestProduct::test_transposed_tensordot
-tests/third_party/cupy/linalg_tests/test_product.py::TestProduct::test_transposed_tensordot_with_int_axes
-tests/third_party/cupy/linalg_tests/test_product.py::TestProduct::test_transposed_tensordot_with_list_axes
 
 tests/third_party/cupy/logic_tests/test_comparison.py::TestArrayEqual::test_array_equal_broadcast_not_allowed
 tests/third_party/cupy/logic_tests/test_comparison.py::TestArrayEqual::test_array_equal_diff_dtypes_is_equal

tests/skipped_tests_gpu.tbl

@@ -437,10 +437,6 @@ tests/third_party/cupy/linalg_tests/test_einsum.py::TestListArgEinSumError::test
 tests/third_party/cupy/linalg_tests/test_product.py::TestMatrixPower::test_matrix_power_invlarge
 tests/third_party/cupy/linalg_tests/test_product.py::TestMatrixPower::test_matrix_power_large
 tests/third_party/cupy/linalg_tests/test_product.py::TestMatrixPower::test_matrix_power_of_two
-tests/third_party/cupy/linalg_tests/test_product.py::TestProduct::test_transposed_tensordot
-tests/third_party/cupy/linalg_tests/test_product.py::TestProduct::test_transposed_tensordot_with_int_axes
-tests/third_party/cupy/linalg_tests/test_product.py::TestProduct::test_transposed_tensordot_with_list_axes
-tests/third_party/cupy/linalg_tests/test_product.py::TestProduct::test_tensordot_zero_dim
 
 tests/third_party/cupy/logic_tests/test_comparison.py::TestArrayEqual::test_array_equal_broadcast_not_allowed
 tests/third_party/cupy/logic_tests/test_comparison.py::TestArrayEqual::test_array_equal_diff_dtypes_is_equal