How to use FFTW: Difference between revisions
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= | [[Category:HowTo]] | ||
== Getting Started == | |||
'''Note that this is done on an Ubuntu operating system, on Windows some steps are different.''' | |||
''' | * '''Step 1''': Download FFTW from http://www.fftw.org/download.html | ||
* | * '''Step 2''': Extract and Configure it (my path: /home/jafarabadi/Documents/fftw-3.3.4) | ||
<pre> | |||
cd /home/jafarabadi/Documents/fftw-3.3.4 | |||
./configure | |||
make | |||
make install | |||
</pre> | |||
* | * Alternatively install fftw through your package manager (e.g. pacman -Sy fftw) | ||
* Step | * '''Step 3''': Add library to project: first open [your_project_name].pro file in Qt Creator and add this line: | ||
<pre> | |||
LIBS += -lfftw3 | |||
</pre> | |||
* '''Step 4''': Example | |||
* | <code> | ||
** | #include <fftw3.h> | ||
int N; | |||
// Set N to the number of complex elements in the input array | |||
fftw_complex *in, *out; | |||
in = (fftw_complex *)fftw_malloc(sizeof(fftw_complex) * N); | |||
out = (fftw_complex *)fftw_malloc(sizeof(fftw_complex) * N); | |||
// Initialize 'in' with N complex entries | |||
fftw_plan my_plan; | |||
my_plan = fftw_plan_dft_1d(N, in, out, FFTW_FORWARD, FFTW_ESTIMATE); | |||
fftw_execute(my_plan); | |||
// Use 'out' for something | |||
fftw_destroy_plan(my_plan); | |||
fftw_free(in); | |||
fftw_free(out); | |||
// A short tutorial: | |||
// http://www2.math.uu.se/~figueras/Other/text/fftw_tutorial.pdf | |||
</code> | |||
Latest revision as of 07:58, 10 March 2017
Getting Started
Note that this is done on an Ubuntu operating system, on Windows some steps are different.
- Step 1: Download FFTW from http://www.fftw.org/download.html
- Step 2: Extract and Configure it (my path: /home/jafarabadi/Documents/fftw-3.3.4)
cd /home/jafarabadi/Documents/fftw-3.3.4 ./configure make make install
- Alternatively install fftw through your package manager (e.g. pacman -Sy fftw)
- 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>
int N;
// Set N to the number of complex elements in the input array
fftw_complex *in, *out;
in = (fftw_complex *)fftw_malloc(sizeof(fftw_complex) * N);
out = (fftw_complex *)fftw_malloc(sizeof(fftw_complex) * N);
// Initialize 'in' with N complex entries
fftw_plan my_plan;
my_plan = fftw_plan_dft_1d(N, in, out, FFTW_FORWARD, FFTW_ESTIMATE);
fftw_execute(my_plan);
// Use 'out' for something
fftw_destroy_plan(my_plan);
fftw_free(in);
fftw_free(out);
// A short tutorial:
// http://www2.math.uu.se/~figueras/Other/text/fftw_tutorial.pdf