One test in data.cc crashes Octave 3.1.51

[Thomas Treichl]

Thomas Treichl schrieb:
> John W. Eaton schrieb:
>> On 12-Aug-2008, Jaroslav Hajek wrote:
>>
>> To start with, run Octave under gdb and find out where it crashes.
> 
> I have some problems here, it looks to me like gdb on my i386 cannot debug PPC 
> code with the Rosetta backend (or at least I don't know how to do it). However, 
> I can see the wrong result (without a crash of Octave) with the i386 binary too. 
> If no other ideas then I'll have a look at that one and send my experiences as 
> soon as possible...

I have had a look at several Mac developer pages but it seems that it won't be 
possible to debug PPC on a 138 on 10.4. So I changed to the i386 binary and also 
have had a look at the Octave sources and I tried to find out more about this 
problem:

The strange thing is that none of the log2 and log10 results for complex numbers 
is correct (but log results seem to e correct). I've found the following code in 
ov-complex.cc which tells me (I hope that I read this correctly) that log and 
log10 are taken from libc++ and log2 is taken from Octave internals?

   COMPLEX_MAPPER (log, std::log)
   COMPLEX_MAPPER (log2, xlog2)
   COMPLEX_MAPPER (log10, std::log10)
   COMPLEX_MAPPER (log1p, ::log1p)

Here is an example output of my Octave session:

   octave-3.1.51+:1> A = complex (0, Inf)
   A =    0 + Infi
   octave-3.1.51+:2> log (A)    ## correct
   ans = Inf + 1.571i
   octave-3.1.51+:3> log1p (A)  ## correct
   ans = Inf + 1.571i
   octave-3.1.51+:4> log2 (A)   ## should be Inf+2.266*i
   ans = Inf - NaNi
   octave-3.1.51+:5> log10 (A)  ## should be Inf+0.682*i
   ans = Inf - NaNi

Different number formats give me the same results:

   octave-3.1.51+:10> log10 (A) ## should be Inf+0.682*i
   ans = Inf - NaNi
   octave-3.1.51+:11> log10 (single (A))
   ans = Inf - NaNi

Hhmmm... Do I have a problem with 'cmath' and its libraries of the gcc 4.0.1 suite?

Regards,

   Thomas