Changeset 1100 for trunk/yat/classifier

Timestamp:

Feb 18, 2008, 5:37:50 AM (15 years ago)

Author:

Peter

Message:

fixes #313 - SVM constructor is void and passing kernel and target in train function instead

Location:

trunk/yat/classifier

Files:

• SVM.cc (modified) (6 diffs)
• SVM.h (modified) (5 diffs)
• SVindex.cc (modified) (1 diff)
• Target.cc (modified) (1 diff)
• Target.h (modified) (1 diff)

trunk/yat/classifier/SVM.cc

@@ -39 +39 @@
 #include <sstream>
 #include <stdexcept>
+#include <string>
 #include <utility>
 #include <vector>
@@ -46 +47 @@
 namespace classifier {  
 
-  SVM::SVM(const KernelLookup& kernel, const Target& target)
-    : alpha_(target.size(),0),
-      bias_(0),
+  SVM::SVM(void)
+    : bias_(0),
       C_inverse_(0),
-      kernel_(&kernel),
+      kernel_(NULL),
       margin_(0),
       max_epochs_(100000),
-      output_(target.size(),0),
-      owner_(false),
-      sample_(target.size()),
-      target_(target),
-      trained_(false),
-      tolerance_(0.00000001)
-  {
-#ifndef NDEBUG
-    assert(kernel.columns()==kernel.rows());
-    assert(kernel.columns()==alpha_.size());
-    for (size_t i=0; i<alpha_.size(); i++) 
-      for (size_t j=0; j<alpha_.size(); j++)
-        assert(kernel(i,j)==kernel(j,i));
-    for (size_t i=0; i<alpha_.size(); i++) 
-      for (size_t j=0; j<alpha_.size(); j++) 
-        assert((*kernel_)(i,j)==(*kernel_)(j,i));
-    for (size_t i = 0; i<kernel_->rows(); i++)
-      for (size_t j = 0; j<kernel_->columns(); j++)
-        if (std::isnan((*kernel_)(i,j)))
-          std::cerr << "SVM: Found nan in kernel: " << i << " " 
-                    << j << std::endl;
-#endif        
-  }
+      tolerance_(0.00000001),
+      trained_(false)
+  {
+  }
+
 
   SVM::~SVM()
   {
-    if (owner_)
+    if (kernel_)
       delete kernel_;
   }
 
+
   const utility::vector& SVM::alpha(void) const
   {
@@ -88 +71 @@
   }
 
+
   double SVM::C(void) const
   {
     return 1.0/C_inverse_;
   }
+
 
   void SVM::calculate_margin(void)
@@ -103 +88 @@
   }
 
+
   const DataLookup2D& SVM::data(void) const
   {
@@ -111 +97 @@
   double SVM::kernel_mod(const size_t i, const size_t j) const
   {
+    assert(kernel_);
+    assert(i<kernel_->rows());
+    assert(i<kernel_->columns());
     return i!=j ? (*kernel_)(i,j) : (*kernel_)(i,j) + C_inverse_;
   }
 
-  SVM* SVM::make_classifier(const DataLookup2D& data,
-                            const Target& target) const
-  {
-    SVM* sc=0;
-    try {
-      const KernelLookup& kernel = dynamic_cast<const KernelLookup&>(data);
-      assert(data.rows()==data.columns());
-      assert(data.columns()==target.size());
-      sc = new SVM(kernel,target);
-      //Copy those variables possible to modify from outside
-      sc->set_C(this->C());
-      sc->max_epochs(max_epochs());
-    }
-    catch (std::bad_cast) {
-      std::string str = 
-        "Error in SVM::make_classifier: DataLookup2D of unexpected class.";
-      throw std::runtime_error(str);
-    }
-  
-    return sc;
-  }
+
+  SVM* SVM::make_classifier(void) const
+  {
+    return new SVM(*this);
+  }
+
 
   long int SVM::max_epochs(void) const
@@ -196 +170 @@
   }
 
-  void SVM::reset(void)
-  {
-    trained_=false;
-    alpha_ = utility::vector(target_.size(), 0);
-  }
-
   int SVM::target(size_t i) const
   {
+    assert(i<target_.size());
     return target_.binary(i) ? 1 : -1;
   }
 
-  void SVM::train(void) 
-  {
+  void SVM::train(const KernelLookup& kernel, const Target& targ) 
+  {
+    if (kernel_)
+      delete kernel_;
+    kernel_ = new KernelLookup(kernel);
+    target_ = targ;
+    
+    alpha_ = utility::vector(targ.size(), 0.0);
+    output_ = utility::vector(targ.size(), 0.0);
     // initializing variables for optimization
     assert(target_.size()==kernel_->rows());

trunk/yat/classifier/SVM.h

@@ -57 +57 @@
   public:
     ///
-    /// Constructor taking the kernel and the target vector as
-    /// input. 
-    ///
-    /// @note if the @a target or @a kernel
-    /// is destroyed the behaviour is undefined.
-    ///
-    SVM(const KernelLookup& kernel, const Target& target);
+    /// \brief Constructor 
+    ///
+    SVM(void);
 
     ///
@@ -73 +69 @@
 
     ///
-    /// If DataLookup2D is not a KernelLookup a bad_cast exception is thrown.
-    ///
-    SVM* make_classifier(const DataLookup2D&, const Target&) const;
+    /// 
+    ///
+    SVM* make_classifier(void) const;
 
     ///
@@ -145 +141 @@
     ///
     double predict(const DataLookupWeighted1D& input) const;
-
-    ///
-    /// @brief Function sets \f$ \alpha=0 \f$ and makes SVM untrained.
-    ///
-    void reset(void);
 
     ///
@@ -187 +178 @@
        @return true if succesful
     */
-    void train();
+    void train(const KernelLookup& kernel, const Target& target);
 
        
@@ -243 +234 @@
     unsigned long int max_epochs_;
     utility::vector output_;
-    bool owner_;
     SVindex sample_;
     Target target_;
-    bool trained_;
     double tolerance_;
+    bool trained_;
 
   };

trunk/yat/classifier/SVindex.cc

@@ -69 +69 @@
     nof_sv_=0;
     size_t nof_nsv=0;
+    vec_.resize(alpha.size());
     for (size_t i=0; i<alpha.size(); i++) 
       if (alpha(i)<tol){

trunk/yat/classifier/Target.cc

@@ -41 +41 @@
 namespace yat {
 namespace classifier {
+
+  Target::Target(void)
+  {
+  }
+  
 
   Target::Target(const std::vector<std::string>& label)

trunk/yat/classifier/Target.h

@@ -42 +42 @@
   /// @brief Class for containing sample labels.
   ///
-
   class Target
   {
   
   public:
+    /**
+      \brief default constructor
+    */
+    Target(void);
+
     ///
     /// @brief Constructor creating target with @a labels