fftΒΆ

The fft function computes the complex Fourier Transformation.

cvFFT = fft(cv)

Return Value

cvFFT is the result of the Fourier Transformation of cv.

Parameters

cv

cv is a real or complex vector.

Comment

If cv is a matrix, all columns will be transformed parallelly.

Example

def Spectrum(signal, rsAbtastfrequenz)
{
    S = fft(signal);
    nS = len(S)/2;
    w = (0:(nS-1))/nS * rsAbtastfrequenz/2;
    return [w', abs(S[1:nS])'];
}

Fs = 100;
t = (1:100)/Fs;
s1 = sin(2*PI*t * 5);
s2 = sin(2*PI*t * 15);
s3 = sin(2*PI*t * 30);
s = s1+s2+s3;
plot(t,s);
rmXY = Spectrum(s, Fs);
plot(rmXY[;1], rmXY[;2]);
../../_images/fft.png

See also

Overview Mathematic, ifft

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