add paddle.gcd and paddle.lcm

python/paddle/__init__.py

@@ -225,6 +225,8 @@
 from .tensor.math import lgamma  # noqa: F401
 from .tensor.math import rad2deg  # noqa: F401
 from .tensor.math import deg2rad  # noqa: F401
+from .tensor.math import gcd  # noqa: F401
+from .tensor.math import lcm  # noqa: F401
 from .tensor.math import diff  # noqa: F401
 from .tensor.math import angle  # noqa: F401
 
@@ -463,6 +465,8 @@
            'atan2',
            'rad2deg',
            'deg2rad',
+           'gcd',
+           'lcm',
            'expand',
            'broadcast_to',
            'ones_like',

python/paddle/fluid/tests/unittests/test_gcd.py

@@ -0,0 +1,93 @@
+#   Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import print_function
+
+import unittest
+import numpy as np
+import paddle
+import paddle.fluid as fluid
+import paddle.fluid.core as core
+from paddle.fluid import Program, program_guard
+from op_test import OpTest
+
+paddle.enable_static()
+
+
+class TestGcdAPI(unittest.TestCase):
+    def setUp(self):
+        self.x_np = 12
+        self.y_np = 20
+        self.x_shape = [1]
+        self.y_shape = [1]
+
+    def test_static_graph(self):
+        startup_program = fluid.Program()
+        train_program = fluid.Program()
+        with fluid.program_guard(startup_program, train_program):
+            x = fluid.data(name='input1', dtype='int32', shape=self.x_shape)
+            y = fluid.data(name='input2', dtype='int32', shape=self.y_shape)
+            out = paddle.gcd(x, y)
+
+            place = fluid.CUDAPlace(0) if core.is_compiled_with_cuda(
+            ) else fluid.CPUPlace()
+            exe = fluid.Executor(place)
+            res = exe.run(fluid.default_main_program(),
+                          feed={'input1': self.x_np,
+                                'input2': self.y_np},
+                          fetch_list=[out])
+            self.assertTrue((np.array(res[0]) == np.gcd(self.x_np, self.y_np)
+                             ).all())
+
+    def test_dygraph(self):
+        paddle.disable_static()
+        x = paddle.to_tensor(self.x_np)
+        y = paddle.to_tensor(self.y_np)
+        result = paddle.gcd(x, y)
+        self.assertEqual(
+            np.allclose(np.gcd(self.x_np, self.y_np), result.numpy()), True)
+
+        paddle.enable_static()
+
+
+class TestGcdAPI2(TestGcdAPI):
+    def setUp(self):
+        self.x_np = np.arange(6).astype(np.int32)
+        self.y_np = np.array([20]).astype(np.int32)
+        self.x_shape = [6]
+        self.y_shape = [1]
+
+
+class TestGcdAPI3(TestGcdAPI):
+    def setUp(self):
+        self.x_np = 0
+        self.y_np = 20
+        self.x_shape = [1]
+        self.y_shape = [1]
+
+
+class TestGcdAPI4(TestGcdAPI):
+    def setUp(self):
+        self.x_np = 0
+        self.y_np = 0
+        self.x_shape = [1]
+        self.y_shape = [1]
+
+
+class TestGcdAPI5(TestGcdAPI):
+    def setUp(self):
+        self.x_np = 12
+        self.y_np = -20
+        self.x_shape = [1]
+        self.y_shape = [1]

python/paddle/fluid/tests/unittests/test_lcm.py

@@ -0,0 +1,93 @@
+#   Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import print_function
+
+import unittest
+import numpy as np
+import paddle
+import paddle.fluid as fluid
+import paddle.fluid.core as core
+from paddle.fluid import Program, program_guard
+from op_test import OpTest
+
+paddle.enable_static()
+
+
+class TestLcmAPI(unittest.TestCase):
+    def setUp(self):
+        self.x_np = 12
+        self.y_np = 20
+        self.x_shape = [1]
+        self.y_shape = [1]
+
+    def test_static_graph(self):
+        startup_program = fluid.Program()
+        train_program = fluid.Program()
+        with fluid.program_guard(startup_program, train_program):
+            x1 = fluid.data(name='input1', dtype='int32', shape=self.x_shape)
+            x2 = fluid.data(name='input2', dtype='int32', shape=self.y_shape)
+            out = paddle.lcm(x1, x2)
+
+            place = fluid.CUDAPlace(0) if core.is_compiled_with_cuda(
+            ) else fluid.CPUPlace()
+            exe = fluid.Executor(place)
+            res = exe.run(fluid.default_main_program(),
+                          feed={'input1': self.x_np,
+                                'input2': self.y_np},
+                          fetch_list=[out])
+            self.assertTrue((np.array(res[0]) == np.lcm(self.x_np, self.y_np)
+                             ).all())
+
+    def test_dygraph(self):
+        paddle.disable_static()
+        x1 = paddle.to_tensor(self.x_np)
+        x2 = paddle.to_tensor(self.y_np)
+        result = paddle.lcm(x1, x2)
+        self.assertEqual(
+            np.allclose(np.lcm(self.x_np, self.y_np), result.numpy()), True)
+
+        paddle.enable_static()
+
+
+class TestLcmAPI2(TestLcmAPI):
+    def setUp(self):
+        self.x_np = np.arange(6).astype(np.int32)
+        self.y_np = np.array([20]).astype(np.int32)
+        self.x_shape = [6]
+        self.y_shape = [1]
+
+
+class TestLcmAPI3(TestLcmAPI):
+    def setUp(self):
+        self.x_np = 0
+        self.y_np = 20
+        self.x_shape = [1]
+        self.y_shape = [1]
+
+
+class TestLcmAPI4(TestLcmAPI):
+    def setUp(self):
+        self.x_np = 0
+        self.y_np = 0
+        self.x_shape = [1]
+        self.y_shape = [1]
+
+
+class TestLcmAPI5(TestLcmAPI):
+    def setUp(self):
+        self.x_np = 12
+        self.y_np = -20
+        self.x_shape = [1]
+        self.y_shape = [1]

python/paddle/tensor/__init__.py

@@ -191,6 +191,8 @@
 from .math import diagonal  # noqa: F401
 from .math import rad2deg  # noqa: F401
 from .math import deg2rad  # noqa: F401
+from .math import gcd  # noqa: F401
+from .math import lcm  # noqa: F401
 from .math import diff  # noqa: F401
 from .math import angle  # noqa: F401
 
@@ -405,6 +407,10 @@
            'multi_dot',
            'solve',
            'triangular_solve',
+           'rad2deg',
+           'deg2rad',
+           'gcd',
+           'lcm',
            'diff',
            'angle',
 ]

python/paddle/tensor/math.py

@@ -2725,6 +2725,139 @@ def deg2rad(x, name=None):
             type='scale', inputs={'X':out_cast}, outputs={'Out': out}, attrs={'scale': deg2rad_scale})
         return out
 
+def gcd(x, y, name=None):
+    """
+    Computes the element-wise greatest common divisor (GCD) of input |x| and |y|.
+    Both x and y must have integer types.
+
+    Note:
+        gcd(0,0)=0, gcd(0, y)=|y|
+
+    Args:
+        x, y (Tensor): An N-D Tensor, the data type is int8，int16，int32，int64，uint8. 
+            If x.shape != y.shape, they must be broadcastable to a common shape (which becomes the shape of the output).
+        name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
+
+    Returns:
+        out (Tensor): An N-D Tensor, the data type is the same with input.
+
+    Examples:
+        .. code-block:: python
+
+            import paddle
+            import numpy as np
+
+            x1 = paddle.to_tensor(12)
+            x2 = paddle.to_tensor(20)
+            paddle.gcd(x1, x2)
+            # Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [4])
+
+            x3 = paddle.to_tensor(np.arange(6))
+            paddle.gcd(x3, x2)
+            # Tensor(shape=[6], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [20, 1 , 2 , 1 , 4 , 5])
+
+            x4 = paddle.to_tensor(0)
+            paddle.gcd(x4, x2)
+            # Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [20])
+
+            paddle.gcd(x4, x4)
+            # Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [0])
+
+            x5 = paddle.to_tensor(-20)
+            paddle.gcd(x1, x5)
+            # Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [4])
+    """
+    shape = paddle.broadcast_shape(x.shape, y.shape)
+    x = paddle.broadcast_to(x, shape)
+    y = paddle.broadcast_to(y, shape)
+    x = paddle.abs(x)
+    y = paddle.abs(y)
+
+    def _gcd_cond_fn(x, y):
+        return paddle.any(y != 0)
+
+    def _gcd_body_fn(x, y):
+        # paddle.mod will raise an error when any element of y is 0. To avoid
+        # that, we change those zeros to ones. Their values don't matter because
+        # they won't be used.
+        y_not_equal_0 = (y != 0)
+        y_safe = paddle.where(y_not_equal_0, y, paddle.ones(y.shape, y.dtype))
+        x, y = (paddle.where(y_not_equal_0, y, x),
+                  paddle.where(y_not_equal_0, paddle.mod(x, y_safe),paddle.zeros(y.shape, y.dtype)))
+        return (paddle.where(x < y, y, x), paddle.where(x < y, x, y))
+
+    if in_dygraph_mode():
+        while _gcd_cond_fn(x, y):
+            x, y = _gcd_body_fn(x, y)
+
+        return x
+    else:
+        check_variable_and_dtype(x, 'x', ['int32', 'int64', 'int8', 'int16', 'uint8'], 'gcd')
+        check_variable_and_dtype(y, 'y', ['int32', 'int64', 'int8', 'int16', 'uint8'], 'gcd')
+        out, _ = paddle.static.nn.while_loop(_gcd_cond_fn, _gcd_body_fn, [x, y])
+        return out
+
+def lcm(x, y, name=None):
+    """
+    Computes the element-wise least common multiple (LCM) of input |x| and |y|.
+    Both x and y must have integer types.
+
+    Note:
+        lcm(0,0)=0, lcm(0, y)=0
+
+    Args:
+        x, y (Tensor): An N-D Tensor, the data type is int8，int16，int32，int64，uint8. 
+            If x.shape != y.shape, they must be broadcastable to a common shape (which becomes the shape of the output).
+        name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
+
+    Returns:
+        out (Tensor): An N-D Tensor, the data type is the same with input.
+
+    Examples:
+        .. code-block:: python
+
+            import paddle
+            import numpy as np
+
+            x1 = paddle.to_tensor(12)
+            x2 = paddle.to_tensor(20)
+            paddle.lcm(x1, x2)
+            # Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [60])
+
+            x3 = paddle.to_tensor(np.arange(6))
+            paddle.lcm(x3, x2)
+            # Tensor(shape=[6], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [0, 20, 20, 60, 20, 20])
+
+            x4 = paddle.to_tensor(0)
+            paddle.lcm(x4, x2)
+            # Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [0])
+
+            paddle.lcm(x4, x4)
+            # Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [0])
+
+            x5 = paddle.to_tensor(-20)
+            paddle.lcm(x1, x5)
+            # Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True,
+            #        [60])
+    """
+    d = paddle.gcd(x, y)
+    # paddle.mod will raise an error when any element of y is 0. To avoid
+    # that, we change those zeros to ones. Their values don't matter because
+    # they won't be used.
+    d_equal_0 = paddle.equal(d, 0)
+    d_safe = paddle.where(d_equal_0, paddle.ones(d.shape, d.dtype), d)
+    out = paddle.where(d_equal_0, paddle.zeros(d.shape, d.dtype), paddle.abs(x * y) // d_safe)
+    return out
+
 def diff(x, n=1, axis=-1, prepend=None, append=None, name=None):
     r"""
     Computes the n-th forward difference along the given axis.