openSUSE:Leap:42.2
openSUSE Leap 42.2
https://download.opensuse.org/distribution/leap/42.2/repo/oss/

perlTestNumberDelta
Compare the difference between numbers against a given tolerance
At some point or another, most programmers find they need to compare
floatingpoint numbers for equality. The typical idiom is to test if the
absolute value of the difference of the numbers is within a desired
tolerance, usually called epsilon. This module provides such a function for
use with the Test::More manpage. Usage is similar to other test functions
described in the Test::More manpage. Semantically, the 'delta_within'
function replaces this kind of construct:
ok ( abs($p  $q) < $epsilon, '$p is equal to $q' ) or
diag "$p is not equal to $q to within $epsilon";
While there's nothing wrong with that construct, it's painful to type it
repeatedly in a test script. This module does the same thing with a single
function call. The 'delta_ok' function is similar, but either uses a global
default value for epsilon or else calculates a 'relative' epsilon on the
fly so that epsilon is scaled automatically to the size of the arguments to
'delta_ok'. Both functions are exported automatically.
Because checking floatingpoint equality is not always reliable, it is not
possible to check the 'equal to' boundary of 'less than or equal to
epsilon'. Therefore, Test::Number::Delta only compares if the absolute
value of the difference is *less than* epsilon (for equality tests) or
*greater than* epsilon (for inequality tests).