Re: Octave 2.9.16 still has failing test for randp(1e9, 1, 6)

[David Bateman]

address@hidden wrote:
> As reported in 
>
>       Debian packages for Octave 2.9.10 available in experimental
>       - Rafael Laboissiere Mar 29, 2007; 06:35am 
>
> the following test was failing; and it's still failing in at least
> 2.9.13, 2.9.15 and 2.9.16.  Here's the 2.9.16 snippet from
> test/fntests.log:
>
>     >>>>> processing /usr/local/src/octave/src/DLD-FUNCTIONS/rand.cc
>       ***** test
>      % Test fixed state
>      randp("seed",1);
>      assert(randp(1e9,1,6),[1000006208 1000012224 999981120 999963520 
> 999963072 999981440])
>     !!!!! test failed
>     error: assert (randp (1e9, 1, 6),[1000006208, 1000012224, 999981120, 
> 999963520, 999963072, 999981440]) expected
>        1.0000e+09   1.0000e+09   9.9998e+08   9.9996e+08   9.9996e+08   
> 9.9998e+08
>     but got
>        1.0000e+09   1.0000e+09   9.9998e+08   9.9996e+08   9.9996e+08   
> 9.9998e+08
>     values do not match
>     shared variables {
>       __random_statistical_tests__ = 0
>     }
>
> It turns out that things are only a "little bit off":
>
>     octave:7> randp("state",1);
>     octave:8> assert(randp(1e9,1,6),[999915677 999976657 1000047684 
> 1000019035 999985749 999977692],1e-6)
>     octave:9> randp("seed",1);
>     octave:10> x= randp(1e9,1,6); y = [1000006208 1000012224 999981120 
> 999963520 999963072 999981440];
>     octave:11> assert(x, y)
>     error: assert (x,y) expected
>        1.0000e+09   1.0000e+09   9.9998e+08   9.9996e+08   9.9996e+08   
> 9.9998e+08
>     but got
>        1.0000e+09   1.0000e+09   9.9998e+08   9.9996e+08   9.9996e+08   
> 9.9998e+08
>     values do not match
>     error: called from `assert' in file 
> `/usr/local/octave/share/octave/2.9.16/m/testfun/assert.m'
>     octave:11> x - y
>     ans =
>
>        17   27  -20   18  -19   -8
>
> Given that there is a working test for large randp and the new "state"
> based generator, it seems that we should change the test to match
> current behavior.
>
> However, if the tests are not repeatable machine to machine (e.g., if
> the sequence of random numbers is not going to be the same on Intel,
> PowerPC, and Sparc 32 and 64 bit platforms), then we shouldn't be making
> those tests (in this way), since they will fail for different platforms.
>
>   
This is the case, they aren't repeatable machine to machine, though I
thought that by reducing the length of the sequence we avoided the
issues we were having.. Perhaps we should just be done with it and add a
relative tolerance of 1e-6 to this test as well..

D.


> /Jskud
>
>   


-- 
David Bateman                                address@hidden
Motorola Labs - Paris                        +33 1 69 35 48 04 (Ph) 
Parc Les Algorithmes, Commune de St Aubin    +33 6 72 01 06 33 (Mob) 
91193 Gif-Sur-Yvette FRANCE                  +33 1 69 35 77 01 (Fax) 

The information contained in this communication has been classified as: 

[x] General Business Information 
[ ] Motorola Internal Use Only 
[ ] Motorola Confidential Proprietary