On using Trapz for a function defined by a variable using syms

Question

Alvin 2017-7-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/349483-on-using-trapz-for-a-function-defined-by-a-variable-using-syms

评论： Alvin 2017-7-19

clear
g = 1;
k = 0.2;
no = 0;
nm = 0;
D = 1;
O = -1;
gam = 0.2;
syms w
xa = -1i.*(w+D)+(k./2);
xb = -1i.*(w-O)+ (gam./2);
xac = conj(xa);
xbc = conj(xb);
c = (1i.*g.*sqrt(k))./(xa.*xb + g.^2);
d = (xa.*sqrt(gam))./(xa.*xb + g.^2);
f(w) = (abs(c).^2).*(no+(1/2))+(abs(d).^2).*(nm+(1/2));
df = diff(f,w);
R = -999:999;
%Q = trapz(R,f(w));
fplot(f(w))
set(gca,'FontSize',14)
title('g = 1, \Delta = 1')
xlabel('\omega')
ylabel('S_{bb}')

Greetings!

I am trying to find the area under a power spectrum. All seems to be well when it comes to plotting it, however as I try to use the Trapz() function, it is giving me the error: Input arguments must be convertible to floating-point numbers. Now I have tried searching for a solution online for a while but I still couldn't solve it. Would appreciate any help possible!

Thank you very much in advance!