如何在R中运行n点FFT？

Question

Suppose I have a length 100 vector x, in Matlab , I can run fft(x,32) to get a length 32 complex vector.

But how to do it in R ?

fft(x,32) will not work and will still return a length 100 complex vector.

Answer 1

From MatLab documentation:

Y = fft(X,n) returns the n-point DFT. If no value is specified, Y is the same size as X.

If X is a vector and the length of X is less than n, then X is padded with trailing zeros to length n.

If X is a vector and the length of X is greater than n, then X is truncated to length n. ...

To achieve same result in R:

fft(x[1:32])