how to find the effective bandwidth of a signal (chirp linear modulated signal)

hello , is the following code correct? if not please tell me the right one

Fs =1000; % Sampling frequency

T = 1/Fs;

L=1000; % length of the signal

t = (0:L-1)*T; % Time vector

x=chirp(t,10,L-1,100,'linear');

f=fft(x);

m=abs(f);

F=(0:L-1)*T;

e=trapz(m.^2);

b=trapz((F.^2).*m.^2);

Beff=(b/e).^0.5

[John D'Errico]

Of course. It does exactly what it does. Why do you think it is not correct?