Re: [Numpy-discussion] FFT definition

2007-02-05 Thread Timothy Hochberg
On 2/5/07, Warren Focke <[EMAIL PROTECTED]> wrote: On Mon, 5 Feb 2007, Timothy Hochberg wrote: > On 2/5/07, Hanno Klemm <[EMAIL PROTECTED]> wrote: > [numpy.fft[ > > The packing of the result is "standard": If A = fft(a, n), then A[0] > > contains the zero-frequency term, A[1:n/2+1] co

Re: [Numpy-discussion] FFT definition

2007-02-05 Thread Warren Focke
On Mon, 5 Feb 2007, Timothy Hochberg wrote: > On 2/5/07, Hanno Klemm <[EMAIL PROTECTED]> wrote: > [numpy.fft[ > > The packing of the result is "standard": If A = fft(a, n), then A[0] > > contains the zero-frequency term, A[1:n/2+1] contains the > > positive-frequency terms, and A[n/2

Re: [Numpy-discussion] FFT definition

2007-02-05 Thread Timothy Hochberg
On 2/5/07, Hanno Klemm <[EMAIL PROTECTED]> wrote: [numpy.fft[ The packing of the result is "standard": If A = fft(a, n), then A[0] contains the zero-frequency term, A[1:n/2+1] contains the positive-frequency terms, and A[n/2+1:] contains the negative-frequency terms, in order of d

Re: [Numpy-discussion] FFT definition

2007-02-05 Thread Warren Focke
The frequencies produced by the two recipies are not the same. But the DFT is periodic in both frequency and time. So whether you think that the number in bin in n/2 should correspond to frequency n/2 or -n/2, it's the same number. w On Mon, 5 Feb 2007, Hanno Klemm wrote: > > Hi there, > > I h

[Numpy-discussion] FFT definition

2007-02-05 Thread Hanno Klemm
Hi there, I have a question regarding the definitions surrounding FFTs. The help to numpy.fft.fft says: >>> help(N.fft.fft) Help on function fft in module numpy.fft.fftpack: fft(a, n=None, axis=-1) fft(a, n=None, axis=-1) Will return the n point discrete Fourier transform of a. n d