MATLAB: Errors Computing the Energy of fft

Question

I am trying to calculate the energy of a Fourier Transform.

gt= 3.*triangularPulse((t-0.004)/0.002)-6.*triangularPulse((t-0.002)/0.001);
Gf1=@(f) abs(fft(gt)).^2; 
EGf=integral(Gf1,0,3000)

However, I keep getting the following errors:

Error using integralCalc/finalInputChecks (line 526)

Output of the function must be the same size as the input. If FUN is an array-valued integrand, set the 'ArrayValued' option to true.

Error in integralCalc/iterateScalarValued (line 315)

finalInputChecks(x,fx);

Error in integralCalc/vadapt (line 132)

[q,errbnd] = iterateScalarValued(u,tinterval,pathlen);

Error in integralCalc (line 75)

[q,errbnd] = vadapt(@AtoBInvTransform,interval);

Error in integral (line 88)

Q = integralCalc(fun,a,b,opstruct);

Answer 1

Hi,

You can check this code. Worked fine for me.

gt= (3.*triangularPulse((t-0.004)/0.002))-(6.*triangularPulse((t-0.002)/0.001));
Gf1=@(f) abs(fft(gt)).^2; 
EGf=integral(Gf1,0,3000,'ArrayValued',1)

Hope it helps !