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Added small utility memcmp_double()

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This commit is contained in:
Joakim Hove 2015-08-12 12:36:33 +02:00
parent 547018d3c7
commit 20968d9c0a
6 changed files with 121 additions and 26 deletions
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2
CMakeLists_files.cmake
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@ -130,6 +130,7 @@ list (APPEND MAIN_SOURCE_FILES
opm/core/utility/VelocityInterpolation.cpp
opm/core/utility/WachspressCoord.cpp
opm/core/utility/miscUtilities.cpp
opm/core/utility/memcmp_double.c
opm/core/utility/miscUtilitiesBlackoil.cpp
opm/core/utility/NullStream.cpp
opm/core/utility/parameters/Parameter.cpp
@ -425,6 +426,7 @@ list (APPEND PUBLIC_HEADER_FILES
opm/core/utility/Exceptions.hpp
opm/core/utility/Factory.hpp
opm/core/utility/MonotCubicInterpolator.hpp
opm/core/utility/memcmp_double.h
opm/core/utility/NonuniformTableLinear.hpp
opm/core/utility/NullStream.hpp
opm/core/utility/RegionMapping.hpp

1
opm/core/grid.h
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@ -302,6 +302,7 @@ read_grid(const char *fname);
bool
grid_equal(const struct UnstructuredGrid * grid1 , const struct UnstructuredGrid * grid2);

26
opm/core/grid/grid.c
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@ -19,6 +19,7 @@
#include "config.h"
#include <opm/core/grid.h>
#include <opm/core/utility/memcmp_double.h>
#include <assert.h>
#include <errno.h>
@ -542,31 +543,6 @@ read_grid(const char *fname)
return G;
}
/**
Ahhh - the joys of comparing floating point numbers ....
http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
*/
static int memcmp_double(const double * p1 , const double *p2 , size_t num_elements) {
if (memcmp(p1 , p2 , num_elements * sizeof * p1) == 0)
return 0;
else {
const double abs_epsilon = 1e-8;
const double rel_epsilon = 1e-5;
for (size_t index = 0; index < num_elements; index++) {
double diff = fabs(p1[index] - p2[index]);
if (diff > abs_epsilon) {
double sum = fabs(p1[index]) + fabs(p2[index]);
if (diff > sum * rel_epsilon)
return 1;
}
}
return 0;
}
}
bool

30
opm/core/utility/memcmp_double.c Normal file
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@ -0,0 +1,30 @@
#include <stdlib.h>
#include <math.h>
#include <string.h>
/**
Ahhh - the joys of comparing floating point numbers ....
http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
*/
int memcmp_double(const double * p1 , const double *p2 , size_t num_elements) {
if (memcmp(p1 , p2 , num_elements * sizeof * p1) == 0)
return 0;
else {
const double abs_epsilon = 1e-8;
const double rel_epsilon = 1e-5;
for (size_t index = 0; index < num_elements; index++) {
double diff = fabs(p1[index] - p2[index]);
if (diff > abs_epsilon) {
double sum = fabs(p1[index]) + fabs(p2[index]);
if (diff > sum * rel_epsilon)
return 1;
}
}
return 0;
}
}

22
opm/core/utility/memcmp_double.h Normal file
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@ -0,0 +1,22 @@
/*
Will compare all the elements in the two double pointers p1 and
p2. If all elements are 'sufficiently' the function will return 0,
otherwise it will return 1.
*/
#ifndef MEMCMP_DOUBLE_H
#define MEMCMP_DOUBLE_H
#ifdef __cplusplus
extern "C" {
#endif
int memcmp_double(const double * p1 , const double *p2 , size_t num_elements);
#ifdef __cplusplus
}
#endif
#endif

64
tests/test_ug.cpp
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@ -19,6 +19,7 @@
#include <algorithm>
#include <vector>
#include <opm/core/grid.h>
#include <opm/core/utility/memcmp_double.h>
#include <opm/core/grid/cornerpoint_grid.h> /* compute_geometry */
#include <opm/core/grid/GridManager.hpp> /* compute_geometry */
#include <opm/core/grid/cpgpreprocess/preprocess.h>
@ -164,3 +165,66 @@ BOOST_AUTO_TEST_CASE(TOPS_Fully_Specified) {
BOOST_CHECK( grid_equal( cgrid1 , cgrid2 ));
}
BOOST_AUTO_TEST_CASE(compare_double) {
const double abs_epsilon = 1e-8;
const double rel_epsilon = 1e-5;
double v1,v2;
/* Should be equal: */
{
v1 = 0.0;
v2 = 0.0;
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 0 );
v1 = 1e-12;
v2 = v1 + 0.5*abs_epsilon;
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 0 );
v1 = 7.0;
v2 = 7.0;
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 0 );
v1 = -7.0;
v2 = -7.0;
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 0 );
v1 = 0;
v2 = 0.5 * abs_epsilon;
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 0 );
v1 = 1e7;
v2 = 1e7 + 2*abs_epsilon;
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 0 );
v1 = 1e7;
v2 = 1e7*(1 + 2*rel_epsilon);
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 0 );
}
/* Should be different: */
{
v1 = 0;
v2 = 1.5 * abs_epsilon;
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 1 );
v1 = 1e-8;
v2 = v1 + 1.5*abs_epsilon;
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 1 );
v1 = 1;
v2 = v1*(1 + 2*rel_epsilon + abs_epsilon);
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 1 );
v1 = 10;
v2 = v1*(1 + 2*rel_epsilon + abs_epsilon);
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 1 );
v1 = 1e7;
v2 = 1e7*(1 + 2*rel_epsilon + abs_epsilon);
BOOST_CHECK_EQUAL( memcmp_double( &v1 , &v2 , 1 ) , 1 );
}
}