Hey guys. I am trying to solve the equation of motion for a 2D 2-point-vortex. Im not sure if i am doing it right and how to plot the answer system. Can anybody look at my script and give some advise? Im quite new to matlab

Here is my coding

Answer 1

[Star Strider]

Your concept is correct. However you are not calculating the derivatives correctly. You have to step through your ‘PtV’ function with individual values of the solved ‘y’-values to calculate the derivatives.

Try this:

for k1 = 1:numel(t)
    ydot(:,k1) = PtV(t(k1),y(k1,:));
end
quiver(y(:,1),y(:,2),ydot(1,:)', ydot(2,:)')
axis equal

The rest of your code appears to be correct, so no changes are needed.