Difference between revisions of "How to use FFTW"

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=How to compute <span class="caps">FFT</span> using <span class="caps">FFTW</span> in Qt=
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[[Category:Learning::HowTo]]
  
==Getting Start==
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= How to compute FFT using FFTW in Qt =
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== Getting Start ==
  
 
'''Note that I do this in Ubuntu operating system, in Windows some steps are different.'''
 
'''Note that I do this in Ubuntu operating system, in Windows some steps are different.'''
  
* Step1: Download <span class="caps">FFTW</span> ([[http:www.fftw.orgdownload.html]])
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* Step1: Download FFTW ([[http://www.fftw.org/download.html]])
  
* Step2: Extract and Configure it (my path: /home/jafarabadi/Documents/fftw-3.3.4)<br />
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* Step2: Extract and Configure it (my path: /home/jafarabadi/Documents/fftw-3.3.4)<br /><code>cd /home/jafarabadi/Documents/fftw-3.3.4<br />chmod ''x configure<br />./configure<br />make<br />make install</code>
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<br />* Step 3: Add library to project: first open [your_project_name].pro file in Qt Creator and add this line:<br /><code>LIBS''= -lfftw3<code>
  
* Step 3: Add library to project: first open [your_project_name].pro file in Qt Creator and add this line:<br />
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* Step 4: Example<br /></code>#include &lt;fftw3.h&amp;gt;</code><br /><code>int N;
  
* Step 4: Example<br />
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fftw_complex *in, '''out;<br />in = (fftw_complex''') fftw_malloc(sizeof(fftw_complex)'''N);<br />out = (fftw_complex''') fftw_malloc(sizeof(fftw_complex)*N);
  
* Step 5: Enjoy <span class="smiley">:)</span> [Written by Ali Jafarabdi :: Qt is an awesome programming language.]
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fftw_plan my_plan;<br />my_plan = fftw_plan_dft_1d(N, in, out, FFTW_FORWARD, FFTW_ESTIMATE);<br />fftw_execute(my_plan);
  
===Categories:===
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fftw_destroy_plan(my_plan);<br />fftw_free(in);<br />fftw_free(out);
  
* [[:Category:Learning|Learning]]
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// A short tutorial: http://www2.math.uu.se/~figueras/fftw_tutorial/text/fftw_tutorial.pdf</code>
** [[:Category:Learning::HowTo|HowTo]]
 

Revision as of 09:57, 24 February 2015


How to compute FFT using FFTW in Qt

Getting Start

Note that I do this in Ubuntu operating system, in Windows some steps are different.

  • Step1: Download FFTW ([[1]])
  • Step2: Extract and Configure it (my path: /home/jafarabadi/Documents/fftw-3.3.4)
    cd /home/jafarabadi/Documents/fftw-3.3.4
    chmod x configure
    ./configure
    make
    make install


* Step 3: Add library to project: first open [your_project_name].pro file in Qt Creator and add this line:
LIBS= -lfftw3

  • Step 4: Example
    #include <fftw3.h&gt;

    int N;

fftw_complex *in, out;
in = (fftw_complex
) fftw_malloc(sizeof(fftw_complex)N);
out = (fftw_complex
) fftw_malloc(sizeof(fftw_complex)*N);

fftw_plan my_plan;
my_plan = fftw_plan_dft_1d(N, in, out, FFTW_FORWARD, FFTW_ESTIMATE);
fftw_execute(my_plan);

fftw_destroy_plan(my_plan);
fftw_free(in);
fftw_free(out);

// A short tutorial: http://www2.math.uu.se/~figueras/fftw_tutorial/text/fftw_tutorial.pdf