Change how model initialization works-- accept empty leaves.

git-svn-id: https://svn.code.sf.net/p/kaldi/code/trunk@876 5e6a8d80-dfce-4ca6-a32a-6e07a63d50c8

src/gmmbin/gmm-init-model.cc

@@ -31,40 +31,39 @@ namespace kaldi {
 /// InitAmGmm initializes the GMM with one Gaussian per state.
 void InitAmGmm(const BuildTreeStatsType &stats,
                const EventMap &to_pdf_map,
-               AmDiagGmm *am_gmm,
-               bool allow_empty_leaves) {
+               AmDiagGmm *am_gmm) {
   // Get stats split by tree-leaf ( == pdf):
   std::vector<BuildTreeStatsType> split_stats;
   SplitStatsByMap(stats, to_pdf_map, &split_stats);
+
   split_stats.resize(to_pdf_map.MaxResult() + 1); // ensure that
   // if the last leaf had no stats, this vector still has the right size.
   
   // Make sure each leaf has stats.
   for (size_t i = 0; i < split_stats.size(); i++) {
     if (split_stats[i].empty()) {
-      std::ostringstream errmsg;
-      errmsg << "Tree has pdf-id " << i << "with no stats. "
-          "This probably means you have phones that were unseen in training "
-          "and were not shared with other phones in the roots file. "
-          "You should modify your roots file as necessary to fix this."
-          "(i.e. share that phone with a similar but seen phone on one line "
-          "of the roots file). Be sure to regenerate roots.int from roots.txt, "
-          "if using s5 scripts. To work out the phone, search for "
-          "pdf-id " << i << " in the output of show-transitions (for this model). ";
-      if (allow_empty_leaves) KALDI_WARN << errmsg.str();
-      else KALDI_ERR << errmsg.str()
-                     << "Use --allow-empty-leaves to make this a warning.";
+      KALDI_WARN << "Tree has pdf-id " << i << "with no stats. ";
+      /*
+        This probably means you have phones that were unseen in training 
+        and were not shared with other phones in the roots file. 
+        You should modify your roots file as necessary to fix this.
+        (i.e. share that phone with a similar but seen phone on one line 
+        of the roots file). Be sure to regenerate roots.int from roots.txt, 
+        if using s5 scripts. To work out the phone, search for 
+        pdf-id  i  in the output of show-transitions (for this model). */
     }
   }
   std::vector<Clusterable*> summed_stats;
   SumStatsVec(split_stats, &summed_stats);
-
+  Clusterable *avg_stats = SumClusterable(summed_stats);
+  KALDI_ASSERT(avg_stats != NULL && "No stats available in gmm-init-model.");
   for (size_t i = 0; i < summed_stats.size(); i++) {
-    assert(summed_stats[i] != NULL);
+    GaussClusterable *c =
+        static_cast<GaussClusterable*>(summed_stats[i] != NULL ? summed_stats[i] : avg_stats);
     DiagGmm gmm;
-    Vector<BaseFloat> x (static_cast<GaussClusterable*>(summed_stats[i])->x_stats());
-    Vector<BaseFloat> x2 (static_cast<GaussClusterable*>(summed_stats[i])->x2_stats());
-    BaseFloat count =  static_cast<GaussClusterable*>(summed_stats[i])->count();
+    Vector<BaseFloat> x (c->x_stats());
+    Vector<BaseFloat> x2 (c->x2_stats());
+    BaseFloat count =  c->count();
     gmm.Resize(1, x.Dim());
     if (count < 100) {
       KALDI_WARN << "Very small count for state "<< i << ": " << count;
@@ -88,6 +87,7 @@ void InitAmGmm(const BuildTreeStatsType &stats,
     am_gmm->AddPdf(gmm);
   }
   DeletePointers(&summed_stats);
+  delete avg_stats;
 }
 
 /// Get state occupation counts.
@@ -219,13 +219,10 @@ int main(int argc, char *argv[]) {
         "  gmm-init-model tree treeacc topo 1.mdl prev/tree prev/30.mdl\n";
 
     bool binary = true;
-    bool allow_empty_leaves = false;
     std::string occs_out_filename;
 
     ParseOptions po(usage);
     po.Register("binary", &binary, "Write output in binary mode");
-    po.Register("allow-empty-leaves", &allow_empty_leaves, "Do not die when there are "
-                "leaves in the tree with no stats.");
     po.Register("write-occs", &occs_out_filename, "File to write state "
                 "occupancies to.");
 
@@ -272,7 +269,7 @@ int main(int argc, char *argv[]) {
     // Now, the summed_stats will be used to initialize the GMM.
     AmDiagGmm am_gmm;
     if (old_tree_filename.empty())
-      InitAmGmm(stats, to_pdf, &am_gmm, allow_empty_leaves);  // Normal case: initialize 1 Gauss/model from tree stats.
+      InitAmGmm(stats, to_pdf, &am_gmm);  // Normal case: initialize 1 Gauss/model from tree stats.
     else {
       InitAmGmmFromOld(stats, to_pdf,
                        ctx_dep.ContextWidth(),