for k = 1:201;
    z(k) = (k-1)*0.1;
    b0(k) = besselj(0,z(k));
    b1(k) = besselj(1,z(k));
    b2(k) = besselj(2,z(k));
    y0(k) = bessely(0,z(k));
    y1(k) = bessely(1,z(k));
    y2(k) = bessely(2,z(k));
    z0(k) = 0;
end
subplot(1,2,1);plot(z,b0,'k-',z,b1,'b-',z,b2,'r-',z,z0,'k:')
axis([0 20 -1 1])
subplot(1,2,2); plot(z,y0,'k-',z,y1,'b-',z,y2,'r-',z,z0,'k:')
axis([0 20 -1 1])