[Rd] bug, feature of mistery?

[Uwe Ligges]

Giuseppe Ragusa wrote:

> Uwe,
> 
> 
> 
>>- Where is *lexical* scoping involved?
> 
> Abuse of "notation". I intended to say scoping.
>  > - Are you really calling you code from a clean workspace?
> Yes it is clean.
> 
>>- Why don't use pass "g" through optim() to f? Please do so, because it 
>>might be a scoping problem.
> 
> Tried that. Still no luck. z<- does not get assigned even if i pass g
> through optim
> 
> 
>>- The .C call in psi() should not matter unless you are doing strange 
>>things in the part you omitted (...).
> 
> 
> I do not think is the call to C. And I did not omit, psi() is the last
> call. And again, same code works fine on the other machine. 

Can you send me a reproducible example (off list), please (inlcuding 
example data)?

Uwe


> 
> 
> On Wed, 11 May 2005, Uwe Ligges wrote:
> 
> 
>>Giuseppe Ragusa wrote:
>>
>>
>>>I have two machines a linux_amd64_x86 (gentoo_amd64) and a linux_x86. Both 
>>>run
>>>R-2.1.0. I have a very long program (hopefully will become a package)
>>>that works perfectly on the linux_amd_x64. Great means no error, no
>>>problems and results that, where the analytic solution exists,
>>>coincide with it. I have problem making the code run on the x64 machine. I
>>>am baffled. The same code on the same version of R, different arch,
>>>is behaving differently. 
>>>
>>>After hour of debugging, I traced down what is triggering the error on
>>>the x86 machine.
>>>
>>>the code snippet is the following similar to:
>>>
>>>R>
>>>g <- h(d)
>>>
>>>f <- function( lambda )
>>>{
>>>z <- g %*% lambda
>>>sum( psi(z) )
>>>...
>>>}
>>>
>>>optim( init.value, f )
>>>
>>>R>
>>>
>>>The function f() is using lexical scoping to get obtain g. The
>>>function psi() is a call to a wrapper function that call a (.C) C
>>>function doing some simple calculation on z. 
>>
>>- Where is *lexical* scoping involved?
>>
>>- Are you really calling you code from a clean workspace?
>>
>>- Why don't use pass "g" through optim() to f? Please do so, because it 
>>might be a scoping problem.
>>
>>- The .C call in psi() should not matter unless you are doing strange 
>>things in the part you omitted (...).
>>
>>Uwe Ligges
>>
>>
>>
>>
>>>What's the problem? When f() is called, g is there, lambda is there,
>>>but the assignment  z <- g %*% lambda results in a matrix of NaN. This
>>>happens from the second time f() is called, i.e. the first time f() is
>>>called from optim() after the C call has been made. The error is then
>>>that passing a NaN vector to .C results in halted execution. 
>>>
>>>If I debug f() during the call to optim, I can without problem assign
>>>z the correct value, but during the execution z is matrix(NaN, nr,
>>>1). 
>>>
>>>At this point I can think of the following:
>>>
>>>1) the external C code has errors 
>>>
>>>It is not a programming error, because when called from console it
>>>  returns the right results. Also, remember, the program work on my
>>>  other machine (the 64 bit);
>>>
>>>2) R error (I do not think so)
>>>
>>>3) Compiling error
>>>Can be the gcc is messing thing around?
>>>
>>>on the 32bit machine
>>>gcc version 3.3.5  (Gentoo Linux 3.3.5-r1, ssp-3.3.2-3, pie-8.7.7.1)
>>>
>>>on the 64-bit machine
>>>gcc version 3.4.3 20041125 (Gentoo Linux 3.4.3-r1, ssp-3.4.3-0, pie-8.7.7)
>>>
>>>Any help, suggestions, thoughts?
>>>
>>>Thank you.
>>>
>>>Giuseppe Ragusa
>>>
>>>______________________________________________
>>>R-devel at stat.math.ethz.ch mailing list
>>>https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>>______________________________________________
>>R-devel at stat.math.ethz.ch mailing list
>>https://stat.ethz.ch/mailman/listinfo/r-devel
> 
>