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      1 // Copyright 2017 The TensorFlow Authors. All Rights Reserved.
      2 //
      3 // Licensed under the Apache License, Version 2.0 (the "License");
      4 // you may not use this file except in compliance with the License.
      5 // You may obtain a copy of the License at
      6 //
      7 //     http://www.apache.org/licenses/LICENSE-2.0
      8 //
      9 // Unless required by applicable law or agreed to in writing, software
     10 // distributed under the License is distributed on an "AS IS" BASIS,
     11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     12 // See the License for the specific language governing permissions and
     13 // limitations under the License.
     14 // =============================================================================
     15 #ifndef TENSORFLOW_CONTRIB_TENSOR_FOREST_KERNELS_V4_INPUT_TARGET_H_
     16 #define TENSORFLOW_CONTRIB_TENSOR_FOREST_KERNELS_V4_INPUT_TARGET_H_
     17 #include "tensorflow/core/framework/tensor.h"
     18 #include "tensorflow/core/framework/tensor_types.h"
     19 
     20 namespace tensorflow {
     21 namespace tensorforest {
     22 
     23 typedef TTypes<float, 1>::UnalignedConstTensor SingleDimStorageType;
     24 
     25 // Base class for classes that hold labels and weights. Mostly for testing
     26 // purposes, because it's inconvenient to construct nasty Eigen::things.
     27 class InputTarget {
     28  public:
     29   virtual ~InputTarget() {}
     30   virtual int32 GetTargetAsClassIndex(int example_index,
     31                                       int target_index) const = 0;
     32 
     33   virtual float GetTargetWeight(int example_index) const = 0;
     34 
     35   virtual float GetTargetAsContinuous(int example_index,
     36                                       int target_index) const = 0;
     37 };
     38 
     39 template <typename T>
     40 class StoredInputTarget : public InputTarget {
     41  protected:
     42   // Takes ownership of t and w with a std::unique_ptr.
     43   StoredInputTarget(const T* t, const T* w, int num_targets)
     44       : target_(t), weight_(w), num_targets_(num_targets) {}
     45 
     46   const std::unique_ptr<const T> target_;
     47   const std::unique_ptr<const T> weight_;
     48   int num_targets_;
     49 };
     50 
     51 // Holds labels/targets and weights. Assumes that tensors are passed as
     52 // t.unaligned_flat<float>(). For multi-output, specifying the number of
     53 // outputs will correctly index the flattened data.
     54 class TensorInputTarget : public StoredInputTarget<SingleDimStorageType> {
     55  public:
     56   TensorInputTarget(const Tensor& target, const Tensor& weight, int num_targets)
     57       : StoredInputTarget(
     58             new SingleDimStorageType(target.unaligned_flat<float>()),
     59             new SingleDimStorageType(weight.unaligned_flat<float>()),
     60             num_targets),
     61         original_tensor_(target) {}
     62 
     63   int32 GetTargetAsClassIndex(int example_index,
     64                               int target_index) const override {
     65     return static_cast<int32>(
     66         GetTargetAsContinuous(example_index, target_index));
     67   }
     68 
     69   float GetTargetWeight(int example_index) const override {
     70     const size_t num_weights = weight_->size();
     71     return num_weights > 0 && example_index < num_weights
     72                ? (*weight_)(example_index)
     73                : 1.0;
     74   }
     75 
     76   float GetTargetAsContinuous(int example_index,
     77                               int target_index) const override {
     78     QCHECK_LT(target_index, num_targets_);
     79     return (*target_)(example_index * num_targets_ + target_index);
     80   }
     81 
     82   const Tensor& original_tensor() const { return original_tensor_; }
     83 
     84  protected:
     85   Tensor original_tensor_;
     86 };
     87 }  // namespace tensorforest
     88 }  // namespace tensorflow
     89 
     90 #endif  // TENSORFLOW_CONTRIB_TENSOR_FOREST_KERNELS_V4_INPUT_TARGET_H_
     91