Error when using abs: Too many input arguments

4 views (last 30 days)
Hi, I am trying to plot the contour of the given function with the following:
syms r x y k z
[ph,r] = meshgrid((0:5:360)*pi/180,0:.5:10);
[X,Y] = pol2cart(ph,r);
Z = X+i*Y;
J = besselj(k,l.*r);
J2 = besselj(k,m.*r);
Y = bessely(k,l.*r);
Y2 = bessely(k,m.*r);
H = besselh(k,r);
F1 = symsum((J).*exp(1i*k*ph),k,-5,5);
F2 = symsum((J2+Y2).*exp(1i.*k.*ph),k,-5,5);
F3 = symsum(H.*exp(1i.*k.*ph),k,-5,5);
pwu = nan(size(F1), 'like', F1);
mask = 0 <= r & r < 0.5;
pwu(mask) = F1(mask);
mask = 0.5 <= r & r < 1;
pwu(mask) = F2(mask);
mask = r >= 1;
pwu(mask) = F3(mask);
U = subs(pwu, {l, m}, {1.5, 3});hold on
axis equal
But I get the error that there too many input arguments. If I remove "double" from the 4th last line, then it says input arguments must be numeric so to be converted to a double. So which way is correct here?

Answers (1)

Dhruv G
Dhruv G on 22 Jun 2021
If you type 'U' in the command window you would find that it is an array of symbolic equations (or expressions I'm not too sure). I think this is happening due to the symsum in your code. This is why it's not possible to cast U into a double and why you're getting the error.
Dhruv G
Dhruv G on 22 Jun 2021
I think if you replace symsum with a function that does what you want numerically it should be possible

Sign in to comment.




Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!