Help using besselh to plot data

Question

0 个投票

Ok so I am trying to plot the Radiation Resistance and Reactance. So i used:

    ka = [0.05, 0.10, 1.00, 2.50, 5.00, 7.50, 10.00];
    syms theta
    x = (2.*ka.*sin(theta));
    R = (1 - ((2*besselj(1,x))./(x)));
    fplot(R)

Which plots fine, but when i to use the one for reactance, the plot window comes up and I get a blank window and no errors.

X = ((2*besselj(1,x))./(x)) + ((j).*((2*bessely(1,x))./(x)));

or

X =@(theta) ((2*besselh(1,1,(2.*ka.*sin(theta))))./((2.*ka.*sin(theta))));
fplot(X)

Any help would be appreciated, Thank you.

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Answer 1

Star Strider 2018-4-26

0 个投票

MATLAB is interpreting ‘j’ here as the imaginary operator:

X = ((2*besselj(1,x))./(x)) + ((j).*((2*bessely(1,x))./(x)));

The MATLAB plot functions (including fplot) will not plot imaginary values. If you want to plot imaginary velues, use the imag function:

figure
fplot(imag(X))