function k = svkernel(ker,u,v)            %  Author: Steve Gunn (srg@ecs.soton.ac.uk)  if (nargin < 1) % check correct number of arguments     help svkernel  else         global p1 p2;    % could check for correct number of args in here    % but will slow things down further    switch lower(ker)      case 'linear'        k = u*v';      case 'poly'        k = (u*v' + 1)^p1;      case 'rbf'        k = exp(-(u-v)*(u-v)'/(2*p1^2));      case 'erbf'        k = exp(-sqrt((u-v)*(u-v)')/(2*p1^2));      case 'waveff'        z= cos(1.75*(u-v)/0.6)*exp(-(abs(u-v))^2/(2*0.6^2));        k = prod(z);      otherwise        k = u*v';    end  end