I am trying to do a grid search for a polynomial kernel. I have used the normal grid search on polynomial kernels which is wrong. I only varied $c$ and $\gamma$... but I need to vary $a$ and $b$... Is there any fast method to do grid search for polynomial kernels?
Polynomial kernel: $K(x_i, x_j) = (\gamma x_i x_j + a)^b,\quad \gamma > 0$
Any suggestions or any corrections as well are welcome.