1 /*

     2 * Portions Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 * The original NIST Statistical Test Suite code is placed in public domain.

    16 * (http://csrc.nist.gov/groups/ST/toolkit/rng/documentation_software.html) 

    17 * 

    18 * This software was developed at the National Institute of Standards and Technology by 

    19 * employees of the Federal Government in the course of their official duties. Pursuant

    20 * to title 17 Section 105 of the United States Code this software is not subject to 

    21 * copyright protection and is in the public domain. The NIST Statistical Test Suite is

    22 * an experimental system. NIST assumes no responsibility whatsoever for its use by other 

    23 * parties, and makes no guarantees, expressed or implied, about its quality, reliability, 

    24 * or any other characteristic. We would appreciate acknowledgment if the software is used.

    25 */

    26 

    27 #include "openc.h"

    28 #include "../include/externs.h"

    29 #include "../include/utilities.h"

    30 #include "../include/cephes.h"

    31 

    32 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

    33          D I S C R E T E  F O U R I E R  T R A N S F O R M  T E S T 

    34  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

    35 void  __ogg_fdrffti(int n, double* wsave, int* ifac);

    36 void  __ogg_fdrfftf(int n, double* X, double* wsave, int* ifac);

    37 

    38 void

    39 DiscreteFourierTransform(int n)

    40 {

    41 	double     p_value, upperBound, percentile, N_l, N_o, d;

    42 	double*    m = NULL;

    43 	double*    X = NULL;

    44 	double*    wsave = NULL;

    45 	int*       ifac = NULL;

    46 	int		i, count;

    47 	

    48 	if ( ((X = (double*) calloc(n,sizeof(double))) == NULL) ||

    49 		 ((wsave = (double *)calloc(2*n+15,sizeof(double))) == NULL) ||

    50 		 ((ifac = (int *)calloc(15,sizeof(int))) == NULL) ||

    51 		 ((m = (double*)calloc(n/2+1, sizeof(double))) == NULL) ) {

    52 			fprintf(stats[7],"\t\tUnable to allocate working arrays for the DFT.\n");

    53 			if( X != NULL )

    54 				free(X);

    55 			if( wsave != NULL )

    56 				free(wsave);

    57 			if( ifac != NULL )

    58 				free(ifac);

    59 			if( m != NULL )

    60 				free(m);

    61 			return;

    62 	}

    63 	for ( i=0; i<n; i++ )

    64 		X[i] = 2*(int)epsilon[i] - 1;

    65 	

    66 	__ogg_fdrffti(n, wsave, ifac);		/* INITIALIZE WORK ARRAYS */

    67 	__ogg_fdrfftf(n, X, wsave, ifac);	/* APPLY FORWARD FFT */

    68 	

    69 	m[0] = sqrt(X[0]*X[0]);	    /* COMPUTE MAGNITUDE */

    70 	

    71 	for ( i=0; i<n/2; i++ ) {	   	    /* DISPLAY FOURIER POINTS */

    72 		m[i+1] = sqrt(pow(X[2*i+1],2)+pow(X[2*i+2],2)); 

    73 	}

    74 	count = 0;				       /* CONFIDENCE INTERVAL */

    75 	upperBound = sqrt(2.995732274*n);

    76 	for ( i=0; i<n/2; i++ )

    77 		if ( m[i] < upperBound )

    78 			count++;

    79 	percentile = (double)count/(n/2)*100;

    80 	N_l = (double) count;       /* number of peaks less than h = sqrt(3*n) */

    81 	N_o = (double) 0.95*n/2.0;

    82 	d = (N_l - N_o)/sqrt(n/2.0*0.95*0.05);

    83 	p_value = erfc(fabs(d)/sqrt(2.0));

    84 

    85 	fprintf(stats[TEST_FFT], "\t\t\t\tFFT TEST\n");

    86 	fprintf(stats[TEST_FFT], "\t\t-------------------------------------------\n");

    87 	fprintf(stats[TEST_FFT], "\t\tCOMPUTATIONAL INFORMATION:\n");

    88 	fprintf(stats[TEST_FFT], "\t\t-------------------------------------------\n");

    89 	fprintf(stats[TEST_FFT], "\t\t(a) Percentile = %f\n", percentile);

    90 	fprintf(stats[TEST_FFT], "\t\t(b) N_l        = %f\n", N_l);

    91 	fprintf(stats[TEST_FFT], "\t\t(c) N_o        = %f\n", N_o);

    92 	fprintf(stats[TEST_FFT], "\t\t(d) d          = %f\n", d);

    93 	fprintf(stats[TEST_FFT], "\t\t-------------------------------------------\n");

    94 

    95 	fprintf(stats[TEST_FFT], "%s\t\tp_value = %f\n\n", p_value < ALPHA ? "FAILURE" : "SUCCESS", p_value);

    96 	fprintf(results[TEST_FFT], "%f\n", p_value);

    97 

    98 	free(X);

    99 	free(wsave);

   100 	free(ifac);

   101 	free(m);

   102 }