--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kerneltest/e32utils/nistsecurerng/src/approximateEntropy.cpp	Tue Aug 31 16:34:26 2010 +0300
@@ -0,0 +1,111 @@
+/*
+* 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/utilities.h"
+#include "../include/cephes.h"  
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+                A P P R O X I M A T E  E N T R O P Y   T E S T
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+void
+ApproximateEntropy(int m, int n)
+{
+	int				i, j, k, r, blockSize, seqLength, powLen, index;
+	double			sum, numOfBlocks, ApEn[2], apen, chi_squared, p_value;
+	unsigned int	*P;
+	
+	fprintf(stats[TEST_APEN], "\t\t\tAPPROXIMATE ENTROPY TEST\n");
+	fprintf(stats[TEST_APEN], "\t\t--------------------------------------------\n");
+	fprintf(stats[TEST_APEN], "\t\tCOMPUTATIONAL INFORMATION:\n");
+	fprintf(stats[TEST_APEN], "\t\t--------------------------------------------\n");
+	fprintf(stats[TEST_APEN], "\t\t(a) m (block length)    = %d\n", m);
+
+	seqLength = n;
+	r = 0;
+	
+	for ( blockSize=m; blockSize<=m+1; blockSize++ ) {
+		if ( blockSize == 0 ) {
+			ApEn[0] = 0.00;
+			r++;
+		}
+		else {
+			numOfBlocks = (double)seqLength;
+			powLen = (int)pow(2, blockSize+1)-1;
+			if ( (P = (unsigned int*)calloc(powLen,sizeof(unsigned int)))== NULL ) {
+				fprintf(stats[TEST_APEN], "ApEn:  Insufficient memory available.\n");
+				return;
+			}
+			for ( i=1; i<powLen-1; i++ )
+				P[i] = 0;
+			for ( i=0; i<numOfBlocks; i++ ) { /* COMPUTE FREQUENCY */
+				k = 1;
+				for ( j=0; j<blockSize; j++ ) {
+					k <<= 1;
+					if ( (int)epsilon[(i+j) % seqLength] == 1 )
+						k++;
+				}
+				P[k-1]++;
+			}
+			/* DISPLAY FREQUENCY */
+			sum = 0.0;
+			index = (int)pow(2, blockSize)-1;
+			for ( i=0; i<(int)pow(2, blockSize); i++ ) {
+				if ( P[index] > 0 )
+					sum += P[index]*log(P[index]/numOfBlocks);
+				index++;
+			}
+			sum /= numOfBlocks;
+			ApEn[r] = sum;
+			r++;
+			free(P);
+		}
+	}
+	apen = ApEn[0] - ApEn[1];
+	
+	chi_squared = 2.0*seqLength*(log(2) - apen);
+	p_value = cephes_igamc(pow(2, m-1), chi_squared/2.0);
+	
+	fprintf(stats[TEST_APEN], "\t\t(b) n (sequence length) = %d\n", seqLength);
+	fprintf(stats[TEST_APEN], "\t\t(c) Chi^2               = %f\n", chi_squared);
+	fprintf(stats[TEST_APEN], "\t\t(d) Phi(m)	       = %f\n", ApEn[0]);
+	fprintf(stats[TEST_APEN], "\t\t(e) Phi(m+1)	       = %f\n", ApEn[1]);
+	fprintf(stats[TEST_APEN], "\t\t(f) ApEn                = %f\n", apen);
+	fprintf(stats[TEST_APEN], "\t\t(g) Log(2)              = %f\n", log(2.0));
+	fprintf(stats[TEST_APEN], "\t\t--------------------------------------------\n");
+
+	if ( m > (int)(log(seqLength)/log(2)-5) ) {
+		fprintf(stats[TEST_APEN], "\t\tNote: The blockSize = %d exceeds recommended value of %d\n", m,
+			MAX(1, (int)(log(seqLength)/log(2)-5)));
+		fprintf(stats[TEST_APEN], "\t\tResults are inaccurate!\n");
+		fprintf(stats[TEST_APEN], "\t\t--------------------------------------------\n");
+	}
+	
+	fprintf(stats[TEST_APEN], "%s\t\tp_value = %f\n\n", p_value < ALPHA ? "FAILURE" : "SUCCESS", p_value);
+	fprintf(results[TEST_APEN], "%f\n", p_value);
+}