public override float Product(SparseVec element1, SparseVec element2)
{
float dot = linKernel.Product(element1, element2);
float prod = (float)Math.Pow((Gamma * dot + Coef), Degree);
return(prod);
}
/// <summary>
/// Computes rbf product, use base calass LinearKernel to compute normal dot product
/// </summary>
/// <param name="element1"></param>
/// <param name="element2"></param>
/// <returns></returns>
public override float Product(SparseVec element1, SparseVec element2)
{
// epx(-g*|x-y|^2) =exp(-g*dot(x-y,x-y))= exp(-g*[ (x1-y1)^2+ ....(xN-yN)^2])
//=exp(-g*( x1^2+...+xN^2 + y1^2+...+yN^2 -2x1y1+...+ -2xNyN))
//float x1Squere = linKernel.Product(element1, element1);
//float x2Squere = linKernel.Product(element2, element2);
float x1Squere = (float)element1.DotProduct();
float x2Squere = (float)element2.DotProduct();
float dot = linKernel.Product(element1, element2);
float prod = (float)Math.Exp(-Gamma * (x1Squere + x2Squere - 2 * dot));
return(prod);
}