function [g] = grad(a,b,ip,iq,ry,rz) 
      
for k=1:ip 
      	g(k)=2.*ry(k+1);
      	for i=1:ip 
		g(k)=g(k)+2.*a(i)*ry(abs(k-i)+1);
	end
end
for l=1:iq 
      	g(ip+l)=-2.*rz(l+1);
      	for i=1:iq 
		g(ip+l)=g(ip+l)-2.*b(i)*rz(abs(l-i)+1);
	end
end