ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Tue, 17 Mar 2015 18:00:59 +0100performing a higher resolution FFThttps://ask.sagemath.org/question/26215/performing-a-higher-resolution-fft/How do I interpolate (up-sample) a discrete function so that I can perform a more refined FFT spectral analysis on it?
(Note: By default, NumPy's FFT command produces a list of the same dimension as the input list.)
thanksTue, 17 Mar 2015 07:13:22 +0100https://ask.sagemath.org/question/26215/performing-a-higher-resolution-fft/Answer by ADuC812 for <p>How do I interpolate (up-sample) a discrete function so that I can perform a more refined FFT spectral analysis on it?</p>
<p>(Note: By default, NumPy's FFT command produces a list of the same dimension as the input list.)</p>
<p>thanks</p>
https://ask.sagemath.org/question/26215/performing-a-higher-resolution-fft/?answer=26218#post-id-26218I am not sure if this is what you want, but if you add some number of zeros in the end of your input list you will get higher resolution (just more points) in the output. This trick works best if your signal decays to zero in the end (and is zero at the beginning). It does not, however, improve the actual resolution of the FFT, for example in case the characteristic frequency in your signal is not an exact multiple of the sampling rate. In the latter case, you can use Hamming window for example to improve resolution.Tue, 17 Mar 2015 14:54:43 +0100https://ask.sagemath.org/question/26215/performing-a-higher-resolution-fft/?answer=26218#post-id-26218Comment by Geremia for <p>I am not sure if this is what you want, but if you add some number of zeros in the end of your input list you will get higher resolution (just more points) in the output. This trick works best if your signal decays to zero in the end (and is zero at the beginning). It does not, however, improve the actual resolution of the FFT, for example in case the characteristic frequency in your signal is not an exact multiple of the sampling rate. In the latter case, you can use Hamming window for example to improve resolution.</p>
https://ask.sagemath.org/question/26215/performing-a-higher-resolution-fft/?comment=26224#post-id-26224Oh, yes, using a windowing function is a good idea. thanksTue, 17 Mar 2015 18:00:59 +0100https://ask.sagemath.org/question/26215/performing-a-higher-resolution-fft/?comment=26224#post-id-26224