Fix to fmllr-diag-gmm.cc; added thresh-post program.

git-svn-id: https://svn.code.sf.net/p/kaldi/code/trunk@889 5e6a8d80-dfce-4ca6-a32a-6e07a63d50c8

src/bin/Makefile

@@ -15,7 +15,7 @@ BINFILES = align-equal align-equal-compiled acc-tree-stats \
         compute-mce-scale get-silence-probs post-to-weights reverse-weights \
         dot-weights sum-tree-stats weight-post post-to-tacc copy-matrix \
         copy-vector copy-int-vector sum-post sum-matrices draw-tree \
-        copy-int-vector-vector \
+        copy-int-vector-vector thresh-post \
         align-mapped align-compiled-mapped latgen-faster-mapped
 
 OBJFILES = 

src/bin/thresh-post.cc

+// bin/thresh-post.cc
+
+// Copyright 2012  Daniel Povey
+
+// 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
+//
+// THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
+// WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
+// MERCHANTABLITY OR NON-INFRINGEMENT.
+// See the Apache 2 License for the specific language governing permissions and
+// limitations under the License.
+
+
+#include "base/kaldi-common.h"
+#include "util/common-utils.h"
+#include "gmm/am-diag-gmm.h"
+#include "hmm/transition-model.h"
+#include "hmm/hmm-utils.h"
+
+
+
+int main(int argc, char *argv[]) {
+  using namespace kaldi;
+  typedef kaldi::int32 int32;
+  try {
+    const char *usage =
+        "Down-weight posteriors that are lower than a supplied confidence threshold.\n"
+        "(for those below the weight, rather than set to zero we downweight according\n"
+        "to the --weight option)\n"
+        "\n"
+        "Usage:  thresh-post [options] <posteriors-rspecifier> <posteriors-wspecifier>\n"
+        "e.g.: thresh-post --threshold=0.9 --scale=0.1 ark:- ark:-\n";
+
+    ParseOptions po(usage);
+
+    BaseFloat threshold = 0.9;
+    BaseFloat scale = 0.1;
+
+    po.Register("threshold", &threshold, "Threshold below which we down-weight posteriors.");
+    po.Register("scale", &scale, "Scale which we apply to posteriors below the threshold.");
+    
+    po.Read(argc, argv);
+
+    if (po.NumArgs() != 2) {
+      po.PrintUsage();
+      exit(1);
+    }
+
+    std::string posteriors_rspecifier = po.GetArg(1),
+        posteriors_wspecifier = po.GetArg(2);
+
+    KALDI_ASSERT(threshold < 1.0 && threshold >= 0.0 && scale >= 0.0 && scale <= 1.0);
+    
+    int32 num_posteriors = 0;
+    double total_weight_in = 0.0, total_weight_out = 0.0;
+    SequentialPosteriorReader posterior_reader(posteriors_rspecifier);
+    PosteriorWriter posterior_writer(posteriors_wspecifier);
+    
+    for (; !posterior_reader.Done(); posterior_reader.Next()) {
+      num_posteriors++;
+      // Posterior is vector<vector<pair<int32, BaseFloat> > >
+      const Posterior &posterior = posterior_reader.Value();
+      // Posterior is vector<vector<pair<int32, BaseFloat> > >
+      Posterior new_post(posterior.size());
+      for (size_t i = 0; i < posterior.size(); i++) {
+        for (size_t j = 0; j < posterior[i].size(); j++) {
+          int32 tid = posterior[i][j].first;
+          double weight = posterior[i][j].second;
+          total_weight_in += weight;
+          if (weight < threshold) weight *= scale;
+          total_weight_out += weight;
+          if (weight != 0.0)
+            new_post[i].push_back(std::make_pair(tid, weight));
+        }
+      }
+      posterior_writer.Write(posterior_reader.Key(), new_post);
+    }
+    KALDI_LOG << "thresh-post: thresholded " << num_posteriors 
+              << " posteriors, reduced them by a factor of "
+              << (total_weight_out/total_weight_in) << " on average.";
+  } catch(const std::exception& e) {
+    std::cerr << e.what();
+    return -1;
+  }
+}
+
+

src/transform/fmllr-diag-gmm.cc

@@ -95,6 +95,7 @@ FmllrDiagGmmAccs::AccumulateForGmm(const DiagGmm &pdf,
   BaseFloat loglike;
   
   loglike = pdf.ComponentPosteriors(data, &posterior);
+  posterior.Scale(weight);
   AccumulateFromPosteriors(pdf, data, posterior);
   return loglike;
 }