www.pudn.com > svm_multiClass.rar > kernel.h

/************************************************************************/ 
/*                                                                      */ 
/*   kernel.h                                                           */ 
/*                                                                      */ 
/*   User defined kernel function. Feel free to plug in your own.       */ 
/*                                                                      */ 
/*   Copyright: Thorsten Joachims                                       */ 
/*   Date: 16.12.97                                                     */ 
/*                                                                      */ 
/************************************************************************/ 
 
/* KERNEL_PARM is defined in svm_common.h The field 'custom' is reserved for */ 
/* parameters of the user defined kernel. You can also access and use */ 
/* the parameters of the other kernels. Just replace the line  
             return((double)(1.0));  
   with your own kernel. */ 
 
  /* Example: The following computes the polynomial kernel. sprod_ss 
              computes the inner product between two sparse vectors.  
 
      return((CFLOAT)pow(kernel_parm->coef_lin*sprod_ss(a->words,b->words) 
             +kernel_parm->coef_const,(double)kernel_parm->poly_degree));  
  */ 
 
/* If you are implementing a kernel that is not based on a 
   feature/value representation, you might want to make use of the 
   field "userdefined" in SVECTOR. By default, this field will contain 
   whatever string you put behind a # sign in the example file. So, if 
   a line in your training file looks like 
 
   -1 1:3 5:6 #abcdefg 
 
   then the SVECTOR field "words" will contain the vector 1:3 5:6, and 
   "userdefined" will contain the string "abcdefg". */ 
 
double custom_kernel(KERNEL_PARM *kernel_parm, SVECTOR *a, SVECTOR *b)  
     /* plug in you favorite kernel */                           
{ 
  return((double)(1.0));  
}