[Rd] bug, feature of mistery?

[Giuseppe Ragusa]

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. 



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

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|Giuseppe Ragusa
|University of California, San Diego
|9500 Gilman Dr. 0508
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|http://weber.ucsd.edu/~gragusa
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