Boost.Test: floating point comparison using absolute diference
Hi all, I am trying to find a way to make the boost unit test framework use an absolute difference for floating point comparison instead of the relative difference. I searched the documentation to try to find a suitable decorator but couldn’t find anything. Any help is much appreciated! #define BOOST_TEST_MODULE example #include <boost/test/included/unit_test.hpp> // boost::unit_test::tolerance uses relative difference and hence this test will pass; // is there anything I can use here to indicate absolute difference? BOOST_AUTO_TEST_CASE(my_test, * boost::unit_test::tolerance(0.1) ) { BOOST_TEST(10.1 == 10.3); }
Le 29.12.17 à 17:33, Georgios Sermaidis via Boost-users a écrit :
Hi all,
I am trying to find a way to make the boost unit test framework use an absolute difference for floating point comparison instead of the relative difference. I searched the documentation to try to find a suitable decorator but couldn’t find anything. Any help is much appreciated!
#defineBOOST_TEST_MODULEexample
#include<boost/test/included/unit_test.hpp>
//boost::unit_test::toleranceusesrelativedifference and hence this test will pass;
// isthereanythingIcanusehereto indicateabsolutedifference?
BOOST_AUTO_TEST_CASE(my_test,*boost::unit_test::tolerance(0.1))
{
BOOST_TEST(10.1==10.3);
}
What you want to do is discussed here in the doc: http://www.boost.org/doc/libs/1_66_0/libs/test/doc/html/boost_test/testing_t... You may just use BOOST_TEST(left - right == .0, boost::unit_test::tolerance(0.1)); and I think it should use absolute tolerance on the absolute value of left-right. If nothing works, there is always the good old comparison: BOOST_TEST((std::abs(left - right) < 0.1)) Note the double parenthesis, in this case BOOST_TEST will see only the evaluation of the expression inside, which is cast to bool (less elegant, but should work as last resort). Raffi
Thank you. Is there a way to achieve this when comparing collections, i.e. when using boost::test_tools::per_element()?
On 29 Dec 2017, at 19:37, Raffi Enficiaud via Boost-users <boost-users@lists.boost.org> wrote:
Le 29.12.17 à 17:33, Georgios Sermaidis via Boost-users a écrit :
Hi all,
I am trying to find a way to make the boost unit test framework use an absolute difference for floating point comparison instead of the relative difference. I searched the documentation to try to find a suitable decorator but couldn’t find anything. Any help is much appreciated!
#defineBOOST_TEST_MODULEexample
#include<boost/test/included/unit_test.hpp>
//boost::unit_test::toleranceusesrelativedifference and hence this test will pass;
// isthereanythingIcanusehereto indicateabsolutedifference?
BOOST_AUTO_TEST_CASE(my_test,*boost::unit_test::tolerance(0.1))
{
BOOST_TEST(10.1==10.3);
}
What you want to do is discussed here in the doc: http://www.boost.org/doc/libs/1_66_0/libs/test/doc/html/boost_test/testing_t...
You may just use
BOOST_TEST(left - right == .0, boost::unit_test::tolerance(0.1));
and I think it should use absolute tolerance on the absolute value of left-right.
If nothing works, there is always the good old comparison: BOOST_TEST((std::abs(left - right) < 0.1))
Note the double parenthesis, in this case BOOST_TEST will see only the evaluation of the expression inside, which is cast to bool (less elegant, but should work as last resort).
Raffi
_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org https://lists.boost.org/mailman/listinfo.cgi/boost-users
Le 30.12.17 à 14:41, Georgios Sermaidis via Boost-users a écrit :
Thank you. Is there a way to achieve this when comparing collections, i.e. when using boost::test_tools::per_element()?
On 29 Dec 2017, at 19:37, Raffi Enficiaud via Boost-users <boost-users@lists.boost.org <mailto:boost-users@lists.boost.org>> wrote:
Le 29.12.17 à 17:33, Georgios Sermaidis via Boost-users a écrit :
Hi all,
I am trying to find a way to make the boost unit test framework use an absolute difference for floating point comparison instead of the relative difference. I searched the documentation to try to find a suitable decorator but couldn’t find anything. Any help is much appreciated!
#defineBOOST_TEST_MODULEexample
#include<boost/test/included/unit_test.hpp>
//boost::unit_test::toleranceusesrelativedifference and hence this test will pass;
// isthereanythingIcanusehereto indicateabsolutedifference?
BOOST_AUTO_TEST_CASE(my_test,*boost::unit_test::tolerance(0.1))
{
BOOST_TEST(10.1==10.3);
}
What you want to do is discussed here in the doc: http://www.boost.org/doc/libs/1_66_0/libs/test/doc/html/boost_test/testing_t...
You may just use
BOOST_TEST(left - right == .0, boost::unit_test::tolerance(0.1));
and I think it should use absolute tolerance on the absolute value of left-right.
If nothing works, there is always the good old comparison: BOOST_TEST((std::abs(left - right) < 0.1))
Note the double parenthesis, in this case BOOST_TEST will see only the evaluation of the expression inside, which is cast to bool (less elegant, but should work as last resort).
Raffi
Apart from creating a collection of differences that you compare with a collection of zeros (that can be wrap up in helper functions), I do not see a way to use this facility as is. Looping over the elements would certainly be the most maintainable and easy to understand choice. Raffi
Got it, thank you so much Regards, Georgios
On 30 Dec 2017, at 22:28, Raffi Enficiaud via Boost-users <boost-users@lists.boost.org> wrote:
Le 30.12.17 à 14:41, Georgios Sermaidis via Boost-users a écrit : Thank you. Is there a way to achieve this when comparing collections, i.e. when using boost::test_tools::per_element()?
On 29 Dec 2017, at 19:37, Raffi Enficiaud via Boost-users <boost-users@lists.boost.org <mailto:boost-users@lists.boost.org>> wrote:
Le 29.12.17 à 17:33, Georgios Sermaidis via Boost-users a écrit : Hi all,
I am trying to find a way to make the boost unit test framework use an absolute difference for floating point comparison instead of the relative difference. I searched the documentation to try to find a suitable decorator but couldn’t find anything. Any help is much appreciated!
#defineBOOST_TEST_MODULEexample
#include<boost/test/included/unit_test.hpp>
//boost::unit_test::toleranceusesrelativedifference and hence this test will pass;
// isthereanythingIcanusehereto indicateabsolutedifference?
BOOST_AUTO_TEST_CASE(my_test,*boost::unit_test::tolerance(0.1))
{
BOOST_TEST(10.1==10.3);
}
What you want to do is discussed here in the doc: http://www.boost.org/doc/libs/1_66_0/libs/test/doc/html/boost_test/testing_t...
You may just use
BOOST_TEST(left - right == .0, boost::unit_test::tolerance(0.1));
and I think it should use absolute tolerance on the absolute value of left-right.
If nothing works, there is always the good old comparison: BOOST_TEST((std::abs(left - right) < 0.1))
Note the double parenthesis, in this case BOOST_TEST will see only the evaluation of the expression inside, which is cast to bool (less elegant, but should work as last resort).
Raffi
Apart from creating a collection of differences that you compare with a collection of zeros (that can be wrap up in helper functions), I do not see a way to use this facility as is. Looping over the elements would certainly be the most maintainable and easy to understand choice.
Raffi
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