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#include "util.h"
using namespace std;
void VectorMatrixMultipy(double *VectorA, double **MatrixB, double *Result, int cols, int rows) //m=1
{
for(int i=0; i<cols; i++)
{
Result[i] = 0;
for(int j=0; j<rows; j++)
{
Result[i] += VectorA[j]*MatrixB[j][i];
}
}
}
void MatrixVectorMultipy(double **MatrixB, double *VectorA, double *Result, int cols, int rows) //m=1
{
for(int i=0; i<rows; i++)
{
Result[i] = 0;
for(int j=0; j<cols; j++)
{
Result[i] += VectorA[j]*MatrixB[i][j];
}
}
}
double arraydot(double *x, double *y, int m)
{
double dot = 0.0;
for(int i =0; i<m; i++)
dot += x[i]*y[i];
return dot;
}
double norm(double *x, int m)
{
double sum = 0.0;
for(int i=0; i<m; i++)
sum += x[i]*x[i];
return sqrt(sum);
}
double norm2(double *x, int m)
{
double sum = 0.0;
for(int i=0; i<m; i++)
sum += x[i]*x[i];
return sum;
}
double getkernel(double *x1, double *x2, double lambda, const char* type, int n)
{
double ker_val = 0.0;
double *diff = new double[n];
for(int i =0; i<n; i++)
{
diff[i] = x1[i] - x2[i];
}
if(strcmp(type, "poly") == 0)
ker_val = pow((arraydot(x1, x2, n)+1),lambda);
else if(strcmp(type, "rbf") == 0)
{
ker_val = exp(-lambda*norm2(diff, n));
}
else
cout<<"\nInvalid kernel type specified in getkernel function!";
delete diff;
return ker_val;
}
bool getfirstkernelderivative(double *x1, double *x2, double lambda, const char* type, int der_wrt, double* der_val, int n)
{
double temp = 0.0;
if(strcmp(type, "poly") == 0)
{
temp = lambda*pow((arraydot(x1, x2, n)+1),(lambda-1));
if(der_wrt == 1)
{
for(int i=0; i<n; i++)
der_val[i] = temp*x2[i];
}
else
{
for(int i=0; i<n; i++)
der_val[i] = temp*x1[i];
}
return true;
}
else if(strcmp(type, "rbf") == 0)
{
double *diff;
diff = new double[n];
for(int i =0; i<n; i++)
diff[i] = x1[i] - x2[i];
if(der_wrt == 1)
{
temp = -2*lambda*exp(-lambda*norm2(diff, n));
}
else
{
temp = 2*lambda*exp(-lambda*norm2(diff, n));
}
for(int i =0; i<n; i++)
der_val[i] = temp*diff[i];
delete diff;
return true;
}
else
{
cout<<"\nInvalid kernel type specified in getkernel function!";
return false;
}
}
bool getsecondkernelderivative(double *x1, double *x2, int n, double lambda, const char *type, double **hesval)
{
if(strcmp(type, "poly") == 0)
{
double tmp = arraydot(x1, x2, n) + 1;
for(int i =0; i< n; i++)
for(int j=0; j< n; j++)
{
if(i == j)
hesval[i][j] = lambda* pow(tmp,(lambda-2))*( tmp + (lambda-1)*x2[i]*x1[j]);
else
hesval[i][j] = lambda* pow(tmp,(lambda-2))*((lambda-1)*x2[i]*x1[j]);
}
return true;
}
else if(strcmp(type, "rbf") == 0)
{
double *tmp1 = new double[n];
for(int i =0; i<n; i++)
tmp1[i] = x1[i] - x2[i];
for(int i = 0; i<n; i++)
for(int j =0; j<n; j++)
if(i == j)
hesval[i][j] = 2*lambda*exp(-lambda*norm2(tmp1,n)) * ( 1 - 2*lambda*(tmp1[i]*tmp1[j]));
else
hesval[i][j] = 2*lambda*exp(-lambda*norm2(tmp1, n)) * (- 2*lambda*(tmp1[i]*tmp1[j]));
delete tmp1;
return true;
}
else
{
cout<<"\nInvalid type specified in the getsecondkernelderivative";
return false;
}
}
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