float comparison
nocide
benutzer at example.com
Sat Aug 25 02:23:44 PDT 2012
Am 25.08.2012 10:36, schrieb Jonathan M Davis:
> On Saturday, August 25, 2012 10:28:44 nocide wrote:
>> unittest {
>> bool fuzzyCmp(float a, float b) {
>> return abs(a-b) < 0.000001f;
>> }
>> float len1 = sqrt(8.0f);
>> float len2 = sqrt(8.0f);
>> assert(len1 == len2); // passes
>> assert(fuzzyCmp(len1,sqrt(8.0f))); // passes
>> assert(len1 == sqrt(8.0f)); // fails!!
>> }
>>
>>
>> The comparison of the float variable passes, but the comparison to the
>> return value of the sqrt-function fails.?!
>
> Comparing floating point numbers with == is almost always the wrong thing to
> do.
>
> http://floating-point-gui.de/
>
> - Jonathan M Davis
>
Many thanks!
nocide
More information about the Digitalmars-d-learn
mailing list