support A-softmax

Author: liuyu

include/caffe/layers/margin_inner_product_layer.hpp

@@ -0,0 +1,70 @@
+#ifndef CAFFE_MARGIN_INNER_PRODUCT_LAYER_HPP_
+#define CAFFE_MARGIN_INNER_PRODUCT_LAYER_HPP_
+
+#include <vector>
+
+#include "caffe/blob.hpp"
+#include "caffe/layer.hpp"
+#include "caffe/proto/caffe.pb.h"
+
+namespace caffe {
+
+/**
+ * @brief Also known as a "marginal fully-connected" layer, computes an marginal inner product
+ *        with a set of learned weights, and (optionally) adds biases.
+ *
+ * TODO(dox): thorough documentation for Forward, Backward, and proto params.
+ */
+template <typename Dtype>
+class MarginInnerProductLayer : public Layer<Dtype> {
+ public:
+  explicit MarginInnerProductLayer(const LayerParameter& param)
+      : Layer<Dtype>(param) {}
+  virtual void LayerSetUp(const vector<Blob<Dtype>*>& bottom,
+      const vector<Blob<Dtype>*>& top);
+  virtual void Reshape(const vector<Blob<Dtype>*>& bottom,
+      const vector<Blob<Dtype>*>& top);
+
+  virtual inline const char* type() const { return "MarginInnerProduct"; }
+  virtual inline int ExactNumBottomBlobs() const { return 2; }
+  virtual inline int MaxTopBlobs() const { return 2; }
+
+ protected:
+  virtual void Forward_cpu(const vector<Blob<Dtype>*>& bottom,
+      const vector<Blob<Dtype>*>& top);
+  virtual void Forward_gpu(const vector<Blob<Dtype>*>& bottom,
+      const vector<Blob<Dtype>*>& top);
+  virtual void Backward_cpu(const vector<Blob<Dtype>*>& top,
+      const vector<bool>& propagate_down, const vector<Blob<Dtype>*>& bottom);
+  virtual void Backward_gpu(const vector<Blob<Dtype>*>& top,
+      const vector<bool>& propagate_down, const vector<Blob<Dtype>*>& bottom);
+
+  int M_;
+  int K_;
+  int N_;
+  
+  MarginInnerProductParameter_MarginType type_;
+
+  // common variables
+  Blob<Dtype> x_norm_;
+  Blob<Dtype> cos_theta_;
+  Blob<Dtype> sign_0_; // sign_0 = sign(cos_theta)
+  // for DOUBLE type
+  Blob<Dtype> cos_theta_quadratic_;
+  // for TRIPLE type
+  Blob<Dtype> sign_1_; // sign_1 = sign(abs(cos_theta) - 0.5)
+  Blob<Dtype> sign_2_; // sign_2 = sign_0 * (1 + sign_1) - 2
+  Blob<Dtype> cos_theta_cubic_;
+  // for QUADRA type
+  Blob<Dtype> sign_3_; // sign_3 = sign_0 * sign(2 * cos_theta_quadratic_ - 1)
+  Blob<Dtype> sign_4_; // sign_4 = 2 * sign_0 + sign_3 - 3
+  Blob<Dtype> cos_theta_quartic_;
+
+  int iter_;
+  Dtype lambda_;
+
+};
+
+}  // namespace caffe
+
+#endif  // CAFFE_MAEGIN_INNER_PRODUCT_LAYER_HPP_