/*

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

* All rights reserved.

* This component and the accompanying materials are made available

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

* which accompanies this distribution, and is available

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

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

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

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

* 

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

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

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

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

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

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

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

*/

#include "openc.h"

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

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

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

		    C U M U L A T I V E  S U M S  T E S T

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

void

CumulativeSums(int n)

{

	int	   S, sup, inf;

	int    z = 0;

	int    zrev = 0;

	int    k;

	double	sum1, sum2, p_value;

	S = 0;

	sup = 0;

	inf = 0;

	for ( k=0; k<n; k++ ) {

		epsilon[k] ? S++ : S--;

		if ( S > sup )

			sup++;

		if ( S < inf )

			inf--;

		z = (sup > -inf) ? sup : -inf;

		zrev = (sup-S > S-inf) ? sup-S : S-inf;

	}

	// forward

	sum1 = 0.0;

	for ( k=(-n/z+1)/4; k<=(n/z-1)/4; k++ ) {

		sum1 += cephes_normal(((4*k+1)*z)/sqrt(n));

		sum1 -= cephes_normal(((4*k-1)*z)/sqrt(n));

	}

	sum2 = 0.0;

	for ( k=(-n/z-3)/4; k<=(n/z-1)/4; k++ ) {

		sum2 += cephes_normal(((4*k+3)*z)/sqrt(n));

		sum2 -= cephes_normal(((4*k+1)*z)/sqrt(n));

	}

	p_value = 1.0 - sum1 + sum2;

	fprintf(stats[TEST_CUSUM], "\t\t      CUMULATIVE SUMS (FORWARD) TEST\n");

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

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

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

	fprintf(stats[TEST_CUSUM], "\t\t(a) The maximum partial sum = %d\n", z);

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

	if ( isNegative(p_value) || isGreaterThanOne(p_value) )

		fprintf(stats[TEST_CUSUM], "\t\tWARNING:  P_VALUE IS OUT OF RANGE\n");

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

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

	// backwards

	sum1 = 0.0;

	for ( k=(-n/zrev+1)/4; k<=(n/zrev-1)/4; k++ ) {

		sum1 += cephes_normal(((4*k+1)*zrev)/sqrt(n));

		sum1 -= cephes_normal(((4*k-1)*zrev)/sqrt(n));

	}

	sum2 = 0.0;

	for ( k=(-n/zrev-3)/4; k<=(n/zrev-1)/4; k++ ) {

		sum2 += cephes_normal(((4*k+3)*zrev)/sqrt(n));

		sum2 -= cephes_normal(((4*k+1)*zrev)/sqrt(n));

	}

	p_value = 1.0 - sum1 + sum2;

	fprintf(stats[TEST_CUSUM], "\t\t      CUMULATIVE SUMS (REVERSE) TEST\n");

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

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

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

	fprintf(stats[TEST_CUSUM], "\t\t(a) The maximum partial sum = %d\n", zrev);

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

	if ( isNegative(p_value) || isGreaterThanOne(p_value) )

		fprintf(stats[TEST_CUSUM], "\t\tWARNING:  P_VALUE IS OUT OF RANGE\n");

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

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

}