maxv=[];
for j=1:N
    startx=(j-1)*d+1;
    endx=startx+d-1;
    block=phi(:,startx:endx);
    t=block'*r;
    maxv(j)=norm(t,2);

y=phi*x;
r=signal-y;

val(i)=norm(r);
err=norm(r)
i=i+1;