FFTW

Purpose:

Example of using FFTW libraries on the cluster. The specific example performs 1D transform.

Contents:

(1) fftw_test.f90: Fortran source code

(2) Makefile: Makefile to compile the source code

(3) fftw_test.sbatch: Btach-job submission script to send the job to the queue

Example Usage:

source new-modules.sh
module load gcc/4.8.2-fasrc01
module load openmpi/1.8.3-fasrc02
module load fftw/3.3.4-fasrc06
make
sbatch fftw_test.sbatch

Example Output:

 Input array:
     in(           1 ) =  (  1.0000000000000000     ,  2.0000000000000000     )
     in(           2 ) =  (  2.0000000000000000     ,  3.0000000000000000     )
     in(           3 ) =  (  3.0000000000000000     ,  4.0000000000000000     )
     in(           4 ) =  (  4.0000000000000000     ,  5.0000000000000000     )
 Output array:
     out(           1 ) =  (  10.000000000000000     ,  14.000000000000000     )
     out(           2 ) =  ( -4.0000000000000000     ,  0.0000000000000000     )
     out(           3 ) =  ( -2.0000000000000000     , -2.0000000000000000     )
     out(           4 ) =  (  0.0000000000000000     , -4.0000000000000000     )
 Output array after inverse FFT:
                4  * in(           1 ) =  (  4.0000000000000000     ,  8.0000000000000000     )
                4  * in(           2 ) =  (  16.000000000000000     ,  20.000000000000000     )
                4  * in(           3 ) =  (  12.000000000000000     ,  16.000000000000000     )
                4  * in(           4 ) =  (  8.0000000000000000     ,  12.000000000000000     )