# FFT data in a file

**URL:** <https://www.ruby-forum.com/t/fft-data-in-a-file/231020>\
**Category:** GNU Radio\
**Created:** [July 17, 2014, 4:36pm UTC](https://www.ruby-forum.com/t/fft-data-in-a-file/231020 "2014-07-17T16:36:12Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [July 17, 2014, 4:36pm UTC](https://www.ruby-forum.com/t/fft-data-in-a-file/231020/1 "2014-07-17T16:36:12Z")

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Hello community,

I am trying to capture the fft data of the received signal in readable  
format. I am very much new to software-radio and USRP and facing some  
difficulties.

Basically I want to plot the captured fft data in the same way uhd\_fft  
does. What is the best way to do that? I have explored  
usrp\_spectrum\_sense.py so far. But, when I plot the output of it (square  
root of m.data), I don’t see it completely matching with the output of  
uhd\_fft. Is there anything else I should try?

Any help regarding this will be highly appreciated.

Sayak