ReClaM: KernelFunction.h Source File

00001 
00002 //===========================================================================
00045 #ifndef _KernelFunction_H_
00046 #define _KernelFunction_H_
00047 
00048 
00049 #include <ReClaM/Model.h>
00050 #include <vector>
00051 
00052 
00085 class KernelFunction : public Model
00086 {
00087 public:
00089     KernelFunction();
00090 
00092     virtual ~KernelFunction();
00093 
00094 
00096     virtual double eval(const Array<double>& x1, const Array<double>& x2) const = 0;
00097 
00100     virtual double evalDerivative(const Array<double>& x1, const Array<double>& x2, Array<double>& derivative) const;
00101 
00103     inline double operator()(const Array<double>& x1, const Array<double>& x2)
00104     {
00105         return eval(x1, x2);
00106     }
00107 
00111     void model(const Array<double>& input, Array<double> &output);
00112 
00115     void modelDerivative(const Array<double>& input, Array<double>& derivative);
00116 
00119     void modelDerivative(const Array<double>& input, Array<double> &output, Array<double>& derivative);
00120 
00121     friend class C_SVM;
00122 };
00123 
00124 
00126 class LinearKernel : public KernelFunction
00127 {
00128 public:
00129     LinearKernel();
00130     ~LinearKernel();
00131 
00132 
00133     double eval(const Array<double>& x1, const Array<double>& x2) const;
00134     double evalDerivative(const Array<double>& x1, const Array<double>& x2, Array<double>& derivative) const;
00135 };
00136 
00137 
00139 class PolynomialKernel : public KernelFunction
00140 {
00141 public:
00142     PolynomialKernel(int degree, double offset);
00143     ~PolynomialKernel();
00144 
00145 
00146     double eval(const Array<double>& x1, const Array<double>& x2) const;
00147 
00148     // TODO (later...)
00149     // Only fill in the derivative w.r.t. the offset?
00150     // double evalDerivative(const Array<double>& x1, const Array<double>& x2, Array<double>& derivative) const;
00151 
00152     void setParameter(unsigned int index, double value);
00153 
00154     bool isFeasible();
00155 };
00156 
00157 
00170 class RBFKernel : public KernelFunction
00171 {
00172 public:
00173     RBFKernel(double gamma);
00174     ~RBFKernel();
00175 
00176 
00177     double eval(const Array<double>& x1, const Array<double>& x2) const;
00178     double evalDerivative(const Array<double>& x1, const Array<double>& x2, Array<double>& derivative) const;
00179 
00180     bool isFeasible();
00181 
00182     double getSigma();
00183     void setSigma(double sigma);
00184 };
00185 
00186 
00188 class NormalizedRBFKernel : public KernelFunction
00189 {
00190 public:
00191     NormalizedRBFKernel();
00192     NormalizedRBFKernel(double s);
00193 
00194 
00195     void setSigma(double s);
00196     double eval(const Array<double> &x,  const Array<double> &z) const;
00197     double evalDerivative(const Array<double> &x,  const Array<double> &z, Array<double>& derivative) const;
00198 };
00199 
00200 
00212 class NormalizedKernel : public KernelFunction
00213 {
00214 public:
00215     NormalizedKernel(KernelFunction* base);
00216     ~NormalizedKernel();
00217 
00218 
00219     void setParameter(unsigned int index, double value);
00220     double eval(const Array<double>& x1, const Array<double>& x2) const;
00221     double evalDerivative(const Array<double>& x1, const Array<double>& x2, Array<double>& derivative) const;
00222 
00223     bool isFeasible();
00224 
00225 protected:
00227     KernelFunction* baseKernel;
00228 };
00229 
00230 
00248 class WeightedSumKernel : public KernelFunction
00249 {
00250 public:
00251     WeightedSumKernel(const std::vector<KernelFunction*>& base);
00252     ~WeightedSumKernel();
00253 
00254 
00255     void setParameter(unsigned int index, double value);
00256     double eval(const Array<double>& x1, const Array<double>& x2) const;
00257     double evalDerivative(const Array<double>& x1, const Array<double>& x2, Array<double>& derivative) const;
00258 
00259     bool isFeasible();
00260 
00261 protected:
00263     std::vector<KernelFunction*> baseKernel;
00264 
00266     std::vector<double> weight;
00267 
00269     double weightsum;
00270 };
00271 
00272 
00290 class WeightedSumKernel2 : public KernelFunction
00291 {
00292 public:
00293     WeightedSumKernel2(const std::vector<KernelFunction*>& base);
00294     ~WeightedSumKernel2();
00295 
00296 
00297     void setParameter(unsigned int index, double value);
00298     double eval(const Array<double>& x1, const Array<double>& x2) const;
00299     double evalDerivative(const Array<double>& x1, const Array<double>& x2, Array<double>& derivative) const;
00300 
00301     bool isFeasible();
00302 
00303 protected:
00304     std::vector<KernelFunction*> baseKernel;
00305 
00306     std::vector<double> weight;
00307 
00308     double weightsum;
00309 };
00310 
00311 
00312 #endif
00313