MATLAB: Plot symbolic function real part

besselplotsreal partsymbolic

Hello there,
I would like to plot the real part of this symbolic function I have just solved.
Parameters 'a' and 'e' are varying between 5 and 9, and 0.05 and 0.15 respectively.
Unfortunately, it does not work.
Here you go with my code ( solution is a ratio of sum of Bessel functions of order zero).
clc
clear
set(groot,'DefaultAxesFontSize',14) 
set(groot,'DefaultLineLineWidth',1.5)
syms a e
A = [besselj(0,-1i*a*e), bessely(0,-1i*a*e); ...
    besselj(0,-1i*a), bessely(0,-1i*a)];
b = [-1; -1];
X = linsolve(A, b);
disp(X)
a = linspace(5,9);
e = linspace(0.05, 0.15);
plot(a, e, X)

Best Answer

You are plotting a function of two variables, so you need to use a plot that accommodates them, and that your function is symbolic.
Try this: 
syms a e
A = [besselj(0,-1i*a*e), bessely(0,-1i*a*e); ...
    besselj(0,-1i*a), bessely(0,-1i*a)];
b = [-1; -1];
X = linsolve(A, b);
disp(X)
a = linspace(5,9);
e = linspace(0.05, 0.15);
fsurf(real(X), [5 9, 0.05 0.15])
xlabel('a')
ylabel('e')
Experiment to get the result you want.
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