.. _program_listing_file_src_optimizers_exponential_smoothing.cpp:

Program Listing for File exponential_smoothing.cpp
==================================================

|exhale_lsh| :ref:`Return to documentation for file <file_src_optimizers_exponential_smoothing.cpp>` (``src/optimizers/exponential_smoothing.cpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #include "common/definitions.h"
   #include "functional/functional.h"
   #include "tensors/tensor_operators.h"
   #include "common/options.h"
   #include "optimizers/optimizers.h"
   #include "optimizers/exponential_smoothing.h"
   
   namespace marian {
   
   void ExponentialSmoothing::updateAvgParams(Tensor paramsAvg, Tensor params, size_t batches, size_t actualBatchTrgWords) {
     double beta = 1. - mvDecayBy_;
   
     // correction term if batch size is different from what mvDecayBy_ was specified for
     if (refBatchTrgWords_ > 0 && actualBatchTrgWords > refBatchTrgWords_) {
       LOG_ONCE(info, "Exponential smoothing gets automatically adjusted as if update size was {} target words", refBatchTrgWords_);
       beta = pow(beta, (double)actualBatchTrgWords / (double)refBatchTrgWords_);
       batches = (size_t)((double)batches * (double)actualBatchTrgWords / (double)refBatchTrgWords_);
     }
   
     // reduce effect of decay parameter in early training stages
     float decayBy = std::max(1.f - (float)beta,
                              1.f - (float)(batches + 1) / (float)(batches + 10));
     using namespace functional;
     Element(_1 = ((1.f - decayBy) * _1) + (decayBy * _2), paramsAvg, params);
   }
   
   }  // namespace marian