Complex functions and flow around a cylinder part 2 (matlab). Full article available at: http://www.firsttimeprogrammer.blogspot.com/2015/07/complex-functions-and-flow-around.html

complex_flow2.m

%%Gradient and flow

figure
subplot(1,2,1);
[Dx, Dy] = gradient(real(z));
Dx(isinf(Dx)) = 0;
Dy(isinf(Dy)) = 0;
hQuiver = quiver(x,y1,Dx,Dy,'LineWidth',1); hold on;
viscircles([0 0],1,'LineWidth',1); hold off;
title('u(x,y) gradient, vector field');

%%Imaginary part
subplot(1,2,2)
contour(x,y1,imag(z),linspace(-10,10,100)); title('Contour of Im(f)');
hold on;
viscircles([0 0],1,'LineWidth',1); hold off;
xlabel('x'); ylabel('y'); %clabel(C3);
title('Imaginary part');