Either way, understanding that it may not be the best way of do it, is
there anything wrong in what I'm doing??
George Vega Yon
+56 9 7 647 2552
http://ggvega.cl
2013/11/5 Gabriel Becker <gmbec...@ucdavis.edu>:
> George,
>
> My point is you don't need to create them and then grow them....
>
>
> for(i=0;i<n;i++)
> {
> // Creating the "id" and "lambda" vectors. I do this in every repetition
> of
> // the loop.
>
> // ... Some other instructions where I set the value of an integer
> // z, which tells how much do the vectors have to grow ...
>
> PROTECT(id=allocVector(INTSXP, 4 +z));
> PROTECT(lambda=allocVector(REALSXP, 4 +z));
>
>
> // ... some lines where I fill the vectors ...
>
> // Storing the new vectors at the i-th element of the list
> SET_VECTOR_ELT(VECTOR_ELT(L1, i), 0, duplicate(id));
> SET_VECTOR_ELT(VECTOR_ELT(L1, i), 1, duplicate(lambda));
>
> // Unprotecting the "id" and "lambda" vectors
> UNPROTECT(2);
> }
>
> ~G
>
>
> On Tue, Nov 5, 2013 at 1:56 PM, George Vega Yon <g.vega...@gmail.com> wrote:
>>
>> Gabriel,
>>
>> While the length (in terms of number of SEXP elements it stores) of L1
>> doesn't changes, the vectors within L1 do (sorry if I didn't explained
>> it well before).
>>
>> The post was about a SEXP object that grows, in my case, every pair of
>> vectors in L1 (id and lambda) can change lengths, this is why I need
>> to reprotect them. I populate the i-th element of L1 by creating the
>> vectors "id" and "lambda", setting the length of these according to
>> some rule (that's the part where lengths change)... here is a reduced
>> form of my code:
>>
>> //////////////////////////////////////// C
>> ////////////////////////////////////////
>> const int = length(L0);
>> SEXP L1;
>> PROTECT(L1 = allocVector(VECSXP,n));
>> SEXP id, lambda;
>>
>> // Fixing size
>> for(i=0;i<n;i++)
>> SET_VECTOR_ELT(L1, i, allocVector(VECSXP, 2));
>>
>> for(i=0;i<n;i++)
>> {
>> // Creating the "id" and "lambda" vectors. I do this in every repetition
>> of
>> // the loop.
>> PROTECT_WITH_INDEX(id=allocVector(INTSXP, 4), &ipx0);
>> PROTECT_WITH_INDEX(lambda=allocVector(REALSXP, 4), &ipx1);
>>
>> // ... Some other instructions where I set the value of an integer
>> // z, which tells how much do the vectors have to grow ...
>>
>> REPROTECT(SET_LENGTH(id, length(lambda) + z), ipx0);
>> REPROTECT(SET_LENGTH(lambda,length(lambda) + z), ipx1);
>>
>> // ... some lines where I fill the vectors ...
>>
>> // Storing the new vectors at the i-th element of the list
>> SET_VECTOR_ELT(VECTOR_ELT(L1, i), 0, duplicate(id));
>> SET_VECTOR_ELT(VECTOR_ELT(L1, i), 1, duplicate(lambda));
>>
>> // Unprotecting the "id" and "lambda" vectors
>> UNPROTECT(2);
>> }
>>
>> UNPROTECT(1);
>>
>> return L1;
>> //////////////////////////////////////// C
>> ////////////////////////////////////////
>>
>> I can't set the length from the start because every pair of vectors in
>> L1 have different lengths, lengths that I cannot tell before starting
>> the loop.
>>
>> Thanks for your help,
>>
>> Regards,
>>
>> George Vega Yon
>> +56 9 7 647 2552
>> http://ggvega.cl
>>
>>
>> 2013/11/5 Gabriel Becker <gmbec...@ucdavis.edu>:
>> > George,
>> >
>> > I don't see the relevance of the stackoverflow post you linked. In the
>> > post,
>> > the author wanted to change the length of an existing "mother list"
>> > (matrix,
>> > etc), while you specifically state that the length of L1 will not
>> > change.
>> >
>> > You say that the child lists (vectors if they are INTSXP/REALSXP) are
>> > variable, but that is not what the linked post was about unless I am
>> > completely missing something.
>> >
>> > I can't really say more without knowing the details of how the vectors
>> > are
>> > being created and why they cannot just have the right length from the
>> > start.
>> >
>> > As for the error, that is a weird one. I imagine it means that a SEXP
>> > thinks
>> > that it has a type other than ones defined in Rinternals. I can't speak
>> > to
>> > how that could have happened from what you posted though.
>> >
>> > Sorry I can't be of more help,
>> > ~G
>> >
>> >
>> >
>> > On Mon, Nov 4, 2013 at 8:00 PM, George Vega Yon <g.vega...@gmail.com>
>> > wrote:
>> >>
>> >> Dear R-devel,
>> >>
>> >> A couple of weeks ago I started to use the R C API for package
>> >> development. Without knowing much about C, I've been able to write
>> >> some routines sucessfully... until now.
>> >>
>> >> My problem consists in dynamically creating a list ("L1") of lists
>> >> using .Call, the tricky part is that each element of the "mother list"
>> >> contains two vectors (INTSXP and REALEXP types) with varying sizes;
>> >> sizes that I set while I'm looping over another list's ("L1") elements
>> >> (input list). The steps I've follow are:
>> >>
>> >> FIRST: Create the "mother list" of size "n=length(L0)" (doesn't
>> >> change) and protect it as
>> >> PROTECT(L1=allocVector(VECEXP, length(L0)))
>> >> and filling it with vectors of length two:
>> >> for(i=0;i<n;i++) SET_VECTOR_ELT(L1,i, allocVector(VECSXP, 2));
>> >>
>> >> then, for each element of the mother list:
>> >>
>> >> for(i=0;i<n;i++) {
>> >>
>> >> SECOND: By reading this post in Stackoverflow
>> >>
>> >>
>> >> http://stackoverflow.com/questions/7458364/growing-an-r-matrix-inside-a-c-loop/7458516#7458516
>> >> I understood that it was necesary to (1) create the "child lists" and
>> >> protecting them with PROTECT_WITH_INDEX, and (2) changing its size
>> >> using SETLENGTH (Rf_lengthgets) and REPROTECT ing the lists in order
>> >> to tell the GC that the vectors had change.
>> >>
>> >> THIRD: Once my two vectors are done ("id" and "lambda"), assign them
>> >> to the i-th element of the "mother list" L1 using
>> >> SET_VECTOR_ELT(VECTOR_ELT(L1,i), 0, duplicate(id));
>> >> SET_VECTOR_ELT(VECTOR_ELT(L1,i), 1, duplicate(lambda));
>> >>
>> >> and unprotecting the elements protected with index: UNPROTECT(2);
>> >>
>> >> }
>> >>
>> >> FOURTH: Unprotecting the "mother list" (L1) and return it to R
>> >>
>> >> With small datasets this works fine, but after trying with bigger ones
>> >> R (my code) keeps failing and returning a strange error that I haven't
>> >> been able to identify (or find in the web)
>> >>
>> >> "unimplemented type (29) in 'duplicate'"
>> >>
>> >> This happens right after I try to use the returned list from my
>> >> routine (trying to print it or building a data-frame).
>> >>
>> >> Does anyone have an idea of what am I doing wrong?
>> >>
>> >> Best regards,
>> >>
>> >> PS: I didn't wanted to copy the entire function... but if you need it
>> >> I can do it.
>> >>
>> >> George Vega Yon
>> >> +56 9 7 647 2552
>> >> http://ggvega.cl
>> >>
>> >> ______________________________________________
>> >> R-devel@r-project.org mailing list
>> >> https://stat.ethz.ch/mailman/listinfo/r-devel
>> >
>> >
>> >
>> >
>> > --
>> > Gabriel Becker
>> > Graduate Student
>> > Statistics Department
>> > University of California, Davis
>
>
>
>
> --
> Gabriel Becker
> Graduate Student
> Statistics Department
> University of California, Davis
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