Merge pull request #16432 from zhoukunsheng/linspace

add linspace op

paddle/fluid/API.spec

@@ -275,6 +275,7 @@ paddle.fluid.layers.has_inf (ArgSpec(args=['x'], varargs=None, keywords=None, de
 paddle.fluid.layers.has_nan (ArgSpec(args=['x'], varargs=None, keywords=None, defaults=None), ('document', '2e53e83127dbfd86e7098bdfe9a549e8'))
 paddle.fluid.layers.isfinite (ArgSpec(args=['x'], varargs=None, keywords=None, defaults=None), ('document', '0a437011c3906079fd8947ed3e52d292'))
 paddle.fluid.layers.range (ArgSpec(args=['start', 'end', 'step', 'dtype'], varargs=None, keywords=None, defaults=None), ('document', '2ec937ede953ded2fdff2675883900bb'))
+paddle.fluid.layers.linspace (ArgSpec(args=['start', 'stop', 'num', 'dtype'], varargs=None, keywords=None, defaults=None), ('document', '495e21e9a848c2d075a102802fc67756'))
 paddle.fluid.layers.While.__init__ (ArgSpec(args=['self', 'cond', 'is_test', 'name'], varargs=None, keywords=None, defaults=(False, None)), ('document', '6adf97f83acf6453d4a6a4b1070f3754'))
 paddle.fluid.layers.While.block (ArgSpec(args=['self'], varargs=None, keywords=None, defaults=None), ('document', '6adf97f83acf6453d4a6a4b1070f3754'))
 paddle.fluid.layers.Switch.__init__ (ArgSpec(args=['self', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '6adf97f83acf6453d4a6a4b1070f3754'))

paddle/fluid/operators/linspace_op.cc

+/* 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. */
+
+#include "paddle/fluid/operators/linspace_op.h"
+
+namespace paddle {
+namespace operators {
+
+class LinspaceOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+  void InferShape(framework::InferShapeContext* ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("Start"),
+                   "Input(Start) of LinspaceOp should not be null.");
+    PADDLE_ENFORCE(ctx->HasInput("Stop"),
+                   "Input(Stop) of LinspaceOp should not be null.");
+    PADDLE_ENFORCE(ctx->HasInput("Num"),
+                   "Input(Num) of LinspaceOp should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("Out"),
+                   "Output(OUt) of LinspaceOp should not be null.");
+
+    auto s_dims = ctx->GetInputDim("Start");
+    PADDLE_ENFORCE((s_dims.size() == 1) && (s_dims[0] == 1),
+                   "The shape of Input(Start) should be [1].");
+
+    auto e_dims = ctx->GetInputDim("Stop");
+    PADDLE_ENFORCE((e_dims.size() == 1) && (e_dims[0] == 1),
+                   "The shape of Input(Stop) should be [1].");
+
+    auto step_dims = ctx->GetInputDim("Num");
+    PADDLE_ENFORCE((step_dims.size() == 1) && (step_dims[0] == 1),
+                   "The shape of Input(Num) should be [1].");
+
+    ctx->SetOutputDim("Out", {-1});
+  }
+
+ protected:
+  framework::OpKernelType GetExpectedKernelType(
+      const framework::ExecutionContext& ctx) const override {
+    framework::LibraryType library_{framework::LibraryType::kPlain};
+    framework::DataLayout layout_ = framework::DataLayout::kAnyLayout;
+    return framework::OpKernelType(
+        ctx.Input<framework::Tensor>("Start")->type(), ctx.device_context(),
+        layout_, library_);
+  }
+};
+
+class LinspaceOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  void Make() override {
+    AddInput("Start",
+             "First entry in the sequence. It is a tensor of shape [1], should "
+             "be of type float32 or float64.");
+    AddInput("Stop",
+             "Last entry in the sequence. It is a tensor of shape [1], should "
+             "be of type float32 or float64.");
+    AddInput("Num",
+             "Number of entry in the sequence. It is a tensor of shape [1], "
+             "should be of type int32.");
+    AddOutput("Out", "A sequence of numbers.");
+    AddComment(R"DOC(
+    Return fixed number of evenly spaced values within a given interval. First entry is start, and last entry is stop. In the case when Num is 1, only Start is returned. Like linspace function of numpy.
+)DOC");
+  }
+};
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OP_WITHOUT_GRADIENT(linspace, ops::LinspaceOp, ops::LinspaceOpMaker);
+REGISTER_OP_CPU_KERNEL(linspace, ops::CPULinspaceKernel<float>,
+                       ops::CPULinspaceKernel<double>);

paddle/fluid/operators/linspace_op.cu

+/* Copyright (c) 2016 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. */
+
+#include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/linspace_op.h"
+#include "paddle/fluid/platform/cuda_primitives.h"
+
+namespace paddle {
+namespace operators {
+
+#define CUDA_1D_KERNEL_LOOP(i, n)                              \
+  for (int i = blockIdx.x * blockDim.x + threadIdx.x; i < (n); \
+       i += blockDim.x * gridDim.x)
+
+template <typename T>
+__global__ void LinspaceKernel(T start, T step, int64_t size, T* out) {
+  CUDA_1D_KERNEL_LOOP(index, size) { out[index] = start + step * index; }
+}
+
+template <typename T>
+__global__ void LinspaceSpecialKernel(T start, T* out) {
+  out[0] = start;
+}
+
+template <typename T>
+class CUDALinspaceKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& context) const override {
+    auto* start_t = context.Input<framework::Tensor>("Start");
+    auto* stop_t = context.Input<framework::Tensor>("Stop");
+    auto* num_t = context.Input<framework::Tensor>("Num");
+    auto* out = context.Output<framework::Tensor>("Out");
+
+    framework::Tensor n;
+    framework::TensorCopy(*start_t, platform::CPUPlace(), &n);
+    T start = n.data<T>()[0];
+    framework::TensorCopy(*stop_t, platform::CPUPlace(), &n);
+    T stop = n.data<T>()[0];
+    framework::TensorCopy(*num_t, platform::CPUPlace(), &n);
+    int32_t num = n.data<int32_t>()[0];
+
+    PADDLE_ENFORCE(num > 0, "The num of linspace op should be larger than 0.");
+
+    out->Resize(framework::make_ddim({num}));
+    T* out_data = out->mutable_data<T>(context.GetPlace());
+
+    T step = 0;
+    if (num != 1) {
+      step = (stop - start) / (num - 1);
+    }
+
+    auto stream = context.cuda_device_context().stream();
+    int block = 512;
+    int grid = (num + block - 1) / block;
+    LinspaceKernel<T><<<grid, block, 0, stream>>>(start, step, num, out_data);
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OP_CUDA_KERNEL(linspace, ops::CUDALinspaceKernel<float>,
+                        ops::CUDALinspaceKernel<double>);

paddle/fluid/operators/linspace_op.h

+/* Copyright (c) 2016 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. */
+
+#pragma once
+#include <functional>
+#include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/math/math_function.h"
+
+namespace paddle {
+namespace operators {
+
+template <typename T>
+class CPULinspaceKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& context) const override {
+    T start = context.Input<framework::Tensor>("Start")->data<T>()[0];
+    T stop = context.Input<framework::Tensor>("Stop")->data<T>()[0];
+    int32_t num = context.Input<framework::Tensor>("Num")->data<int32_t>()[0];
+    auto* out = context.Output<framework::Tensor>("Out");
+    PADDLE_ENFORCE(num > 0, "The num of linspace op should be larger than 0.");
+
+    out->Resize(framework::make_ddim({num}));
+
+    T* out_data = out->mutable_data<T>(context.GetPlace());
+
+    if (num > 1) {
+      T step = (stop - start) / (num - 1);
+      T value = start;
+      for (int i = 0; i < num; ++i) {
+        out_data[i] = value;
+        value += step;
+      }
+    } else {
+      out_data[0] = start;
+    }
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle

python/paddle/fluid/layers/tensor.py

@@ -24,26 +24,11 @@ from .layer_function_generator import templatedoc
 import numpy
 
 __all__ = [
-    'create_tensor',
-    'create_parameter',
-    'create_global_var',
-    'cast',
-    'tensor_array_to_tensor',
-    'concat',
-    'sums',
-    'assign',
-    'fill_constant_batch_size_like',
-    'fill_constant',
-    'argmin',
-    'argmax',
-    'argsort',
-    'ones',
-    'zeros',
-    'reverse',
-    'has_inf',
-    'has_nan',
-    'isfinite',
-    'range',
+    'create_tensor', 'create_parameter', 'create_global_var', 'cast',
+    'tensor_array_to_tensor', 'concat', 'sums', 'assign',
+    'fill_constant_batch_size_like', 'fill_constant', 'argmin', 'argmax',
+    'argsort', 'ones', 'zeros', 'reverse', 'has_inf', 'has_nan', 'isfinite',
+    'range', 'linspace'
 ]
 
 
@@ -826,3 +811,45 @@ def range(start, end, step, dtype):
                 'Step': step},
         outputs={'Out': [out]})
     return out
+
+
+def linspace(start, stop, num, dtype):
+    """
+    Return fixed number of evenly spaced values within a given interval.
+
+    First entry is start, and last entry is stop. In the case when Num is 1, only Start is returned. Like linspace function of numpy.
+
+    Args:
+        start(float|Variable): First entry in the sequence. It is a float scalar, or a tensor of shape [1] with type 'float32'|'float64'.
+        stop(float|Variable): Last entry in the sequence. It is a float scalar, or a tensor of shape [1] with type 'float32'|'float64'.
+        num(int|Variable): Number of entry in the sequence. It is an int scalar, or a tensor of shape [1] with type int32.
+        dtype(string): 'float32'|'float64', the data type of the output tensor.
+
+    Returns:
+        Variable: The tensor variable storing a 1-D tensor. 
+
+    Examples:
+        .. code-block:: python
+
+             data = fluid.layers.linspace(0, 10, 5, 'float32') # [0.0,  2.5,  5.0,  7.5, 10.0]
+             data = fluid.layers.linspace(0, 10, 1, 'float32') # [0.0]
+
+    """
+    helper = LayerHelper("linspace", **locals())
+
+    if not isinstance(start, Variable):
+        start = fill_constant([1], dtype, start)
+    if not isinstance(stop, Variable):
+        stop = fill_constant([1], dtype, stop)
+    if not isinstance(num, Variable):
+        num = fill_constant([1], 'int32', num)
+
+    out = helper.create_variable_for_type_inference(dtype=start.dtype)
+
+    helper.append_op(
+        type='linspace',
+        inputs={'Start': start,
+                'Stop': stop,
+                'Num': num},
+        outputs={'Out': [out]})
+    return out

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

@@ -1925,6 +1925,13 @@ class TestBook(LayerTest):
             out = layers.flatten(x, axis=1, name="flatten")
             return (out)
 
+    def test_linspace(self):
+        program = Program()
+        with program_guard(program):
+            out = layers.linspace(20, 10, 5, 'float64')
+            self.assertIsNotNone(out)
+        print(str(program))
+
 
 if __name__ == '__main__':
     unittest.main()

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

+#   Copyright (c) 2018 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
+from op_test import OpTest
+
+
+class TestLinspaceOpCommonCase(OpTest):
+    def setUp(self):
+        self.op_type = "linspace"
+        dtype = 'float32'
+        self.inputs = {
+            'Start': np.array([0]).astype(dtype),
+            'Stop': np.array([10]).astype(dtype),
+            'Num': np.array([11]).astype('int32')
+        }
+
+        self.outputs = {'Out': np.arange(0, 11).astype(dtype)}
+
+    def test_check_output(self):
+        self.check_output()
+
+
+class TestLinspaceOpReverseCase(OpTest):
+    def setUp(self):
+        self.op_type = "linspace"
+        dtype = 'float32'
+        self.inputs = {
+            'Start': np.array([10]).astype(dtype),
+            'Stop': np.array([0]).astype(dtype),
+            'Num': np.array([11]).astype('int32')
+        }
+
+        self.outputs = {'Out': np.arange(10, -1, -1).astype(dtype)}
+
+    def test_check_output(self):
+        self.check_output()
+
+
+class TestLinspaceOpNumOneCase(OpTest):
+    def setUp(self):
+        self.op_type = "linspace"
+        dtype = 'float32'
+        self.inputs = {
+            'Start': np.array([10]).astype(dtype),
+            'Stop': np.array([0]).astype(dtype),
+            'Num': np.array([1]).astype('int32')
+        }
+
+        self.outputs = {'Out': np.array(10, dtype=dtype)}
+
+    def test_check_output(self):
+        self.check_output()
+
+
+if __name__ == "__main__":
+    unittest.main()