/********************************************************************
 * Research Computing Center
 * The University of Chicago
 * Edelstone Center
 * 6030 S. Ellis Avenue, Room 126
 * Chicago, IL 60637
 * 773-795-2667
 * rcc@uchicago.edu
 *
 * Author: Douglas Rudd
 * CNET: drudd
 *
 * Created: Tue Jul 10 
 ********************************************************************/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <fftw.h>

int main( int argc, char *argv[] ) {
	int fft_size;
	fftw_plan p;
	fftw_complex *in, *out;

	if ( argc != 2 ) {
		fprintf(stderr,"Usage: ./a.out N (size of fft)\n");
		exit(1);
	}

	/* allocate space and initialize complex array to transform */
	fft_size = atoi(argv[1]);
	in = (fftw_complex *)malloc( sizeof(fftw_complex)*fft_size );
	out = (fftw_complex *)malloc( sizeof(fftw_complex)*fft_size );

	if ( in == NULL || out == NULL ) {
		fprintf(stderr,"Unable to allocate space for arrays!\n");
		exit(1);
	}
	memset( in, 0, fft_size*sizeof(fftw_complex) );
	
	/* create fftw plan, compute fft, and destroy plan */
	p = fftw_create_plan( fft_size, FFTW_FORWARD, 
			FFTW_ESTIMATE | FFTW_OUT_OF_PLACE );
	fftw_one( p, in, out );
	fftw_destroy_plan(p);

	free(in);
	free(out);

	return 0;
}