Merge branch 'develop' of https://github.com/PaddlePaddle/paddle into...

Merge branch 'develop' of https://github.com/PaddlePaddle/paddle into enhance-lookup_table_op-padidx

paddle/gserver/layers/PriorBox.cpp

@@ -65,14 +65,19 @@ bool PriorBoxLayer::init(const LayerMap& layerMap,
   std::copy(pbConf.aspect_ratio().begin(),
             pbConf.aspect_ratio().end(),
             std::back_inserter(tmp));
-  // flip
-  int inputRatioLength = tmp.size();
-  for (int index = 0; index < inputRatioLength; index++) {
-    aspectRatio_.push_back(tmp[index]);
-    aspectRatio_.push_back(1 / tmp[index]);
+
+  if (maxSize_.size() > 0) CHECK_EQ(minSize_.size(), maxSize_.size());
+
+  // flip aspect ratios
+  for (int index = 0; index < tmp.size(); index++) {
+    real ar = tmp[index];
+    if (fabs(ar - 1.) < 1e-6) continue;
+    aspectRatio_.push_back(ar);
+    aspectRatio_.push_back(1. / ar);
   }
-  numPriors_ = aspectRatio_.size();
-  if (maxSize_.size() > 0) numPriors_++;
+
+  numPriors_ = aspectRatio_.size() * minSize_.size() + maxSize_.size();
+
   return true;
 }
 
@@ -99,50 +104,39 @@ void PriorBoxLayer::forward(PassType passType) {
     for (int w = 0; w < layerWidth; ++w) {
       real centerX = (w + 0.5) * stepW;
       real centerY = (h + 0.5) * stepH;
-      real minSize = 0;
       for (size_t s = 0; s < minSize_.size(); s++) {
-        // first prior.
-        minSize = minSize_[s];
+        real minSize = minSize_[s];
         real boxWidth = minSize;
         real boxHeight = minSize;
-        // xmin, ymin, xmax, ymax.
-        tmpPtr[idx++] = (centerX - boxWidth / 2.) / imageWidth;
-        tmpPtr[idx++] = (centerY - boxHeight / 2.) / imageHeight;
-        tmpPtr[idx++] = (centerX + boxWidth / 2.) / imageWidth;
-        tmpPtr[idx++] = (centerY + boxHeight / 2.) / imageHeight;
-        // set the variance.
-        for (int t = 0; t < 4; t++) tmpPtr[idx++] = variance_[t];
+
+        // priors with different aspect ratios
+        for (size_t r = 0; r < aspectRatio_.size(); r++) {
+          real ar = aspectRatio_[r];
+          boxWidth = minSize * sqrt(ar);
+          boxHeight = minSize / sqrt(ar);
+          tmpPtr[idx++] = (centerX - boxWidth / 2.) / imageWidth;
+          tmpPtr[idx++] = (centerY - boxHeight / 2.) / imageHeight;
+          tmpPtr[idx++] = (centerX + boxWidth / 2.) / imageWidth;
+          tmpPtr[idx++] = (centerY + boxHeight / 2.) / imageHeight;
+          // set the variance.
+          for (int t = 0; t < 4; t++) tmpPtr[idx++] = variance_[t];
+        }
 
         if (maxSize_.size() > 0) {
-          CHECK_EQ(minSize_.size(), maxSize_.size());
-          // second prior.
-          for (size_t s = 0; s < maxSize_.size(); s++) {
-            real maxSize = maxSize_[s];
-            boxWidth = boxHeight = sqrt(minSize * maxSize);
-            tmpPtr[idx++] = (centerX - boxWidth / 2.) / imageWidth;
-            tmpPtr[idx++] = (centerY - boxHeight / 2.) / imageHeight;
-            tmpPtr[idx++] = (centerX + boxWidth / 2.) / imageWidth;
-            tmpPtr[idx++] = (centerY + boxHeight / 2.) / imageHeight;
-            // set the variance.
-            for (int t = 0; t < 4; t++) tmpPtr[idx++] = variance_[t];
-          }
+          // square prior with size sqrt(minSize * maxSize)
+          real maxSize = maxSize_[s];
+          boxWidth = boxHeight = sqrt(minSize * maxSize);
+          tmpPtr[idx++] = (centerX - boxWidth / 2.) / imageWidth;
+          tmpPtr[idx++] = (centerY - boxHeight / 2.) / imageHeight;
+          tmpPtr[idx++] = (centerX + boxWidth / 2.) / imageWidth;
+          tmpPtr[idx++] = (centerY + boxHeight / 2.) / imageHeight;
+          // set the variance.
+          for (int t = 0; t < 4; t++) tmpPtr[idx++] = variance_[t];
         }
       }
-      // rest of priors.
-      for (size_t r = 0; r < aspectRatio_.size(); r++) {
-        real ar = aspectRatio_[r];
-        if (fabs(ar - 1.) < 1e-6) continue;
-        real boxWidth = minSize * sqrt(ar);
-        real boxHeight = minSize / sqrt(ar);
-        tmpPtr[idx++] = (centerX - boxWidth / 2.) / imageWidth;
-        tmpPtr[idx++] = (centerY - boxHeight / 2.) / imageHeight;
-        tmpPtr[idx++] = (centerX + boxWidth / 2.) / imageWidth;
-        tmpPtr[idx++] = (centerY + boxHeight / 2.) / imageHeight;
-        // set the variance.
-        for (int t = 0; t < 4; t++) tmpPtr[idx++] = variance_[t];
-      }
     }
   }
+
   // clip the prior's coordidate such that it is within [0, 1]
   for (int d = 0; d < dim * 2; ++d)
     if ((d % 8) < 4)

paddle/operators/math/sampler.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+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 "sampler.h"
+
+namespace paddle {
+namespace random {
+
+Sampler::~Sampler() {}
+
+UniformSampler::UniformSampler(int64 range)
+    : Sampler(range), inv_range_(1.0 / range) {
+  random_engine_ = std::make_shared<std::mt19937>(seed_);
+  dist_ = std::make_shared<std::uniform_int_distribution<>>(0, range);
+}
+
+UniformSampler::UniformSampler(int64 range, unsigned int seed)
+    : Sampler(range, seed), inv_range_(1.0 / range) {
+  random_engine_ = std::make_shared<std::mt19937>(seed_);
+  dist_ = std::make_shared<std::uniform_int_distribution<>>(0, range);
+}
+
+int64 UniformSampler::Sample() const { return (*dist_)(*random_engine_); }
+
+float UniformSampler::Probability(int64 value) const { return inv_range_; }
+
+LogUniformSampler::LogUniformSampler(int64 range)
+    : Sampler(range), log_range_(log(range + 1)) {
+  random_engine_ = std::make_shared<std::mt19937>(seed_);
+  dist_ = std::make_shared<std::uniform_real_distribution<>>(0, 1);
+}
+
+LogUniformSampler::LogUniformSampler(int64 range, unsigned int seed)
+    : Sampler(range, seed), log_range_(log(range + 1)) {
+  random_engine_ = std::make_shared<std::mt19937>(seed_);
+  dist_ = std::make_shared<std::uniform_real_distribution<>>(0, 1);
+}
+int64 LogUniformSampler::Sample() const {
+  // Got Log Uniform distribution from uniform distribution by
+  // inverse_transform_sampling method
+  // More details:
+  // https://wanghaoshuang.github.io/2017/11/Log-uniform-distribution-sampler/
+  const int64 value =
+      static_cast<int64>(exp((*dist_)(*random_engine_) * log_range_)) - 1;
+  // Mathematically, value should be <= range_, but might not be due to some
+  // floating point roundoff, so we mod by range_.
+  return value % range_;
+}
+
+float LogUniformSampler::Probability(int64 value) const {
+  // Given f(x) = 1/[(x+1) * log_range_]
+  // The value's  probability  is integral of f(x) from value to (value + 1)
+  // More details:
+  // https://wanghaoshuang.github.io/2017/11/Log-uniform-distribution-sampler
+  return (log((value + 2.0) / (value + 1.0))) / log_range_;
+}
+
+}  // namespace random
+}  // namespace paddle

paddle/operators/math/sampler.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+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 <memory>
+#include <random>
+typedef long int64;
+namespace paddle {
+namespace operators {
+namespace math {
+
+// TODO(wanghaoshuang): Support for GPU
+
+/**
+* Sample integers from [0, range).
+*/
+class Sampler {
+ public:
+  explicit Sampler(int64 range) : range_(range) {
+    PADDLE_ENFORCE_GT(range, 0);
+    std::random_device r;
+    seed_ = r();
+  }
+  explicit Sampler(int64 range, unsigned int seed)
+      : range_(range), seed_(seed) {
+    PADDLE_ENFORCE_GT(range, 0);
+  }
+  virtual ~Sampler();
+  // Sample a single value
+  virtual int64 Sample() const = 0;
+  // The probability that a single call to Sample() returns the given value.
+  virtual float Probability(int64 value) const = 0;
+
+  int64 range() { return range_; };
+
+ protected:
+  const int64 range_;
+  unsigned int seed_;
+};
+
+/**
+ * Sample integers from [0, range).
+ * And the distribution function is:
+ * P(x) = 1 / range
+ */
+class UniformSampler : public Sampler {
+ public:
+  explicit UniformSampler(int64 range);
+
+  explicit UniformSampler(int64 range, unsigned int seed);
+
+  ~UniformSampler() override {}
+
+  int64 Sample() const override;
+
+  float Probability(int64 value) const override;
+
+ private:
+  const float inv_range_;
+  std::shared_ptr<std::mt19937_64> random_engine_;
+  std::shared_ptr<std::uniform_int_distribution<>> dist_;
+};
+
+/**
+ * Sample integers from [0, range).
+ * And the distribution function is:
+ * P(x) = (1/ln(range+1)) * ln(1 + 1/(x + 1))
+ */
+class LogUniformSampler : public Sampler {
+ public:
+  explicit LogUniformSampler(int64 range);
+
+  explicit LogUniformSampler(int64 range, unsigned int seed);
+
+  ~LogUniformSampler() override {}
+
+  int64 Sample() const override;
+
+  float Probability(int64 value) const override;
+
+ private:
+  const float log_range_;
+  std::shared_ptr<std::mt19937_64> random_engine_;
+  std::shared_ptr<std::uniform_real_distribution<>> dist_;
+};
+
+}  // math
+}  // namespace operators
+}  // namespace paddle