Files
openmm/platforms/reference/tests/TestReferenceRandom.cpp
2008-08-14 21:44:56 +00:00

82 lines
3.7 KiB
C++

/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
/**
* This tests the reference implementation of random number generation.
*/
#include "../../../tests/AssertionUtilities.h"
#include "../src/SimTKUtilities/SimTKOpenMMUtilities.h"
#include <iostream>
using namespace OpenMM;
using namespace std;
void testGaussian() {
mt_init(0);
const int numValues = 10000000;
double mean = 0.0;
double var = 0.0;
double skew = 0.0;
double kurtosis = 0.0;
unsigned long jran = 12399103;
for (int i = 0; i < numValues; i++) {
double value = SimTKOpenMMUtilities::getNormallyDistributedRandomNumber();
mean += value;
var += value*value;
skew += value*value*value;
kurtosis += value*value*value*value;
}
mean /= numValues;
var /= numValues;
skew /= numValues;
kurtosis /= numValues;
double c2 = var-mean*mean;
double c3 = skew-3*var*mean+2*mean*mean*mean;
double c4 = kurtosis-4*skew*mean-3*var*var+12*var*mean*mean-6*mean*mean*mean*mean;
ASSERT_EQUAL_TOL(0.0, mean, 0.01);
ASSERT_EQUAL_TOL(1.0, c2, 0.01);
ASSERT_EQUAL_TOL(0.0, c3, 0.01);
ASSERT_EQUAL_TOL(0.0, c4, 0.01);
}
int main() {
try {
testGaussian();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}