[mlpack-svn] r17442 - mlpack/trunk/src/mlpack/methods/sparse_coding

[fastlab-svn at coffeetalk-1.cc.gatech.edu]

Author: marcus
Date: Thu Dec  4 16:38:04 2014
New Revision: 17442

Log:
Add maxIterations parameter to limit the number of iterations used in the Newton method.

Modified:
   mlpack/trunk/src/mlpack/methods/sparse_coding/sparse_coding.hpp
   mlpack/trunk/src/mlpack/methods/sparse_coding/sparse_coding_impl.hpp

Modified: mlpack/trunk/src/mlpack/methods/sparse_coding/sparse_coding.hpp
==============================================================================
--- mlpack/trunk/src/mlpack/methods/sparse_coding/sparse_coding.hpp	(original)
+++ mlpack/trunk/src/mlpack/methods/sparse_coding/sparse_coding.hpp	Thu Dec  4 16:38:04 2014
@@ -144,11 +144,14 @@
    *    the coding matrix Z that are non-zero (the adjacency matrix for the
    *    bipartite graph of points and atoms).
    * @param newtonTolerance Tolerance of the Newton's method optimizer.
+   * @param maxIterations Maximum number of iterations to run the Newton's method.
+   *     If 0, the method will run until convergence (or forever).
    * @return the norm of the gradient of the Lagrange dual with respect to
    *    the dual variables
    */
   double OptimizeDictionary(const arma::uvec& adjacencies,
-                            const double newtonTolerance = 1e-6);
+                            const double newtonTolerance = 1e-6,
+                            const size_t maxIterations = 50);
 
   /**
    * Project each atom of the dictionary back onto the unit ball, if necessary.

Modified: mlpack/trunk/src/mlpack/methods/sparse_coding/sparse_coding_impl.hpp
==============================================================================
--- mlpack/trunk/src/mlpack/methods/sparse_coding/sparse_coding_impl.hpp	(original)
+++ mlpack/trunk/src/mlpack/methods/sparse_coding/sparse_coding_impl.hpp	Thu Dec  4 16:38:04 2014
@@ -119,7 +119,8 @@
 template<typename DictionaryInitializer>
 double SparseCoding<DictionaryInitializer>::OptimizeDictionary(
     const arma::uvec& adjacencies,
-    const double newtonTolerance)
+    const double newtonTolerance,
+    const size_t maxIterations)
 {
   // Count the number of atomic neighbors for each point x^i.
   arma::uvec neighborCounts = arma::zeros<arma::uvec>(data.n_cols, 1);
@@ -207,7 +208,7 @@
   }
 
   double normGradient;
-  double improvement;
+  double improvement = 0;
   for (size_t t = 1; !converged; ++t)
   {
     arma::mat A = codesZT + diagmat(dualVars);
@@ -228,7 +229,7 @@
     const double rho = 0.9;
     double sufficientDecrease = c * dot(gradient, searchDirection);
 
-    while (true)
+    for (size_t t = 1; t != maxIterations; ++t)
     {
       // Calculate objective.
       double sumDualVars = arma::sum(dualVars);