[mlpack-svn] r16349 - mlpack/tags/mlpack-1.0.8/src/mlpack/methods/nmf
fastlab-svn at coffeetalk-1.cc.gatech.edu
fastlab-svn at coffeetalk-1.cc.gatech.edu
Sun Mar 9 00:07:41 EST 2014
Author: rcurtin
Date: Sun Mar 9 00:07:40 2014
New Revision: 16349
Log:
Handle NaNs better.
Modified:
mlpack/tags/mlpack-1.0.8/src/mlpack/methods/nmf/mult_div_update_rules.hpp
Modified: mlpack/tags/mlpack-1.0.8/src/mlpack/methods/nmf/mult_div_update_rules.hpp
==============================================================================
--- mlpack/tags/mlpack-1.0.8/src/mlpack/methods/nmf/mult_div_update_rules.hpp (original)
+++ mlpack/tags/mlpack-1.0.8/src/mlpack/methods/nmf/mult_div_update_rules.hpp Sun Mar 9 00:07:40 2014
@@ -75,10 +75,18 @@
t2.set_size(H.n_cols);
for (size_t k = 0; k < t2.n_elem; ++k)
{
+ // This may produce NaNs if V(i, k) = 0.
+ // Technically the math in the paper does not define what to do in
+ // this case, but considering the basic intent of the update rules,
+ // we'll make this modification and take t2(k) = 0.0.
t2(k) = H(j, k) * V(i, k) / t1(i, k);
+ if (t2(k) != t2(k))
+ t2(k) = 0.0;
}
- W(i, j) = W(i, j) * sum(t2) / sum(H.row(j));
+ // Only update if the sum is not going to be 0, so as to prevent a
+ // divide by zero. If sum(H.row(j)) is 0, then t2 should be 0 too.
+ W(i, j) *= sum(t2) / sum(H.row(j));
}
}
}
@@ -126,10 +134,18 @@
t2.set_size(W.n_rows);
for (size_t k = 0; k < t2.n_elem; ++k)
{
+ // This may produce NaNs if V(i, k) = 0.
+ // Technically the math in the paper does not define what to do in
+ // this case, but considering the basic intent of the update rules,
+ // we'll make this modification and take t2(k) = 0.0.
t2(k) = W(k, i) * V(k, j) / t1(k, j);
+ if (t2(k) != t2(k))
+ t2(k) = 0.0;
}
- H(i,j) = H(i,j) * sum(t2) / sum(W.col(i));
+ // Only update if the sum is not going to be 0, so as to prevent a
+ // divide by zero. If sum(W.col(j)) is 0, then t2 should be 0 too.
+ H(i, j) *= sum(t2) / sum(W.col(i));
}
}
}
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