# Specifying fft in standard fft call

**URL:** <https://discourse.julialang.org/t/specifying-fft-in-standard-fft-call/5023>\
**Category:** General Usage\
**Tags:** fftw\
**Created:** [July 22, 2017, 7:51pm UTC](https://discourse.julialang.org/t/specifying-fft-in-standard-fft-call/5023 "2017-07-22T19:51:57Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![standarddeviant](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/standarddeviant/32/2309_2.png) [@standarddeviant](https://discourse.julialang.org/u/standarddeviant)\
**Post date:** [July 22, 2017, 7:51pm UTC](https://discourse.julialang.org/t/specifying-fft-in-standard-fft-call/5023/1 "2017-07-22T19:51:57Z")

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I feel like I’m missing something. I have a length 1024 vector and want to take the FFT of that vector. I would like to take a length 2048 FFT of that vector. Is the proper solution to zero-pad the vector manually, and then take the FFT?

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**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [July 22, 2017, 8:02pm UTC](https://discourse.julialang.org/t/specifying-fft-in-standard-fft-call/5023/2 "2017-07-22T20:02:10Z")

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Depends on what you mean mathematically by “the length-2048 FFT” of a length-1024 vector; you are not using standard mathematical terms. `fft` computes a discrete Fourier transform (DFT); what you do with it is up to you.