Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Calculate only first half of IFFT

Posted on 2014-11-20
6
Medium Priority
?
153 Views
Last Modified: 2015-02-02
When calculating the inverse fourier transform using IFFT on a data set where all phases are 0 you obtain a waveform that is symmetrical - the first half of the waveform is the same as the second half mirrored and inverted.

Thus it would be trivial to calculate the second half, given the first half.

Given these conditions, is it possible to calculate IFFT in a way that generates only the first half of the output data in order to reduce computation time?
0
Comment
Question by:JasonMewes
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
6 Comments
 
LVL 84

Accepted Solution

by:
ozo earned 2000 total points
ID: 40455125
Are you now calculating it in a way that prevents you from generating only the first half?
Can you do only a sin transform and ignore cosine?
0
 

Author Comment

by:JasonMewes
ID: 40455260
I am using an implementation very similar to https://github.com/xcore/sc_dsp_transforms/blob/master/module_fft_simple/src/fftcomplex.xc

I cannot see a straight forward way to modify the algorithm for the purpose described, but given your response I assume it should be possible.
0
 
LVL 84

Expert Comment

by:ozo
ID: 40455287
It is possible.  Whether a given implementation offers such a possibility depends on the implementation.
0
 

Author Comment

by:JasonMewes
ID: 40455364
I understand.

Question as stated is considered answered.

Any chance though you would consider looking at the linked algorithm and give me a pointer in the right direction (knowing macs is multiply accumulate)?
0

Featured Post

On Demand Webinar: Networking for the Cloud Era

Did you know SD-WANs can improve network connectivity? Check out this webinar to learn how an SD-WAN simplified, one-click tool can help you migrate and manage data in the cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

One of Google's most recent algorithm changes affecting local searches is entitled "The Pigeon Update." This update has dramatically enhanced search inquires for the keyword "Yelp." Google searches with the word "Yelp" included will now yield Yelp a…
This article provides a brief introduction to tissue engineering, the process by which organs can be grown artificially. It covers the problems with organ transplants, the tissue engineering process, and the current successes and problems of the tec…
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
I've attached the XLSM Excel spreadsheet I used in the video and also text files containing the macros used below. https://filedb.experts-exchange.com/incoming/2017/03_w12/1151775/Permutations.txt https://filedb.experts-exchange.com/incoming/201…
Suggested Courses

660 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question