[Gcl-devel] Re: [Maxima] Float, bug 2688847 and testsuite

[Camm Maguire]

Greetings!  These rounding errors were fixed in the latest stable gcl
source, which is post lenny.  Debian testing has synchronous
gcl/maxima/acl2/axiom/hol88 without errors (on about 12 different
platforms). 

cvs -z9 -q -d:pserver:address@hidden co -d gcl-2.6.8pre -r
Version_2_6_8pre gcl
cd gcl-2.6.8pre && ./configure --enable-ansi && make

Take care,

Paulo Gomes <address@hidden> writes:

> Hello,
>
> I have just succesfully built maxima 5.21.1 from source with gcl in
> Debian 5.0 lenny.
> I ran the test suite and all tests completed with 'Which was correct',
> except these two:
>
> Running tests in rtest16:
> ********************** Problem 180 ***************
> Input:
> float((2^60-1)/2^60)-1
> Result:
> -1.1102230246251565*10^-16
> This differed from the expected result:
> 0.0
> ********************** Problem 181 ***************
> Input:
> float((2^1000-1)/2^1000)-1
> Result:
> -1.1102230246251565*10^-16
> This differed from the expected result:
> 0.0
> 373/375 tests passed
> The following 2 problems failed: (180 181)
> Error summary:
> Errors found in /usr/share/maxima/5.21.1/tests/rtest16.mac, problems:
> (180 181)
> 2 tests failed out of 375 total tests.
>
>
> According to the comment in the testsuite code, this is meant to test
> for a known bug:
> /*
> * Bug [ 2688847 ] float of rats rounds incorrectly
> */
> float((2^60-1)/2^60)-1;
> 0.0;
> float((2^1000-1)/2^1000)-1;
> 0.0;
>
>
> However, the sourceforge maxima bug tracker
>
> http://sourceforge.net/tracker/index.php?func=detail&aid=2688847&group_id=4933&atid=104933
>
> states that this bug is fixed and closed.
>
> Do any of you have an explanation (or have found the same)?
>
> Thank you,
>
> Paulo Gomes
>
>
> _______________________________________________
> Maxima mailing list
> address@hidden
> http://www.math.utexas.edu/mailman/listinfo/maxima
>
>
>
>

-- 
Camm Maguire                                        address@hidden
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