similar to: C++: Appending Values onto an R-Vector.

In a C++ extension to R (v 1.8.1), I've been experimenting with a generic "push back" function to tack one value at a time onto the end of an R vector created within the extension. After calling this function a certain number of times Rgui.exe (I'm writing in Windows using Visual Studio .NET 2003) will fail with an Access Violation, which doesn't happen when I pre-allocate

Hello all, thanks for all the help on the other issues. This one should be relatively straightforward. I have a vector of integers which I allocate to be the maximal size possible (meaning I'll never see more than cel.GetNumOutliers, but most likely I'll see less) therefore, I want to resize the vector, one solution would be to allocate a new vector then to copy into the new vector. That

Dear R Gurus, I would very much appreciate some help with this code snippit from my RODBC package. R crashes or exhibits bizarre behaviour when repeatedly fetching large numbers of rows. Examples: > odbcFetchRows(0,max=50000)->xx > odbcFetchRows(0,max=50000)->xx > odbcFetchRows(0,max=50000)->xx > odbcFetchRows(0,max=50000)->xx > odbcFetchRows(0,max=50000)->xx 3rd

Hello. I'm trying to read a delimited file. I'm a little new to the R api. In the program, I do something like this... /*****************************/ SEXP retval; PROTECT(retval = allocMatrix(STRSXP,1,names.dim)); int r_eltctr = 0; while(!myfile.eof()) { SET_LENGTH(retval,r_eltctr+num_of_fields); for(int i = 0;numofcolumns; ++i) { INTEGER(retval)[r_eltctr++] = 1;/*some

Hi, I want to read a text file into R with .Call(). So I define some NEW_CHARACTER() to store the chracters read and use SET_STRING_ELT to fill the elements. e.g. PROTECT(qNames = NEW_CHARACTER(10000)); char *foo; // This foo holds the string I want. while(foo = readLine(FN)){ SET_STRING_ELT(qNames, i, mkChar(foo))); } In this way, I can get the desired character from qNames. The only problem

Hi! I want to return a matrix. The code does the R interfacing. This version does it fine. SEXP ans,dim; PROTECT(ans = NEW_NUMERIC(count*2)); memcpy(NUMERIC_POINTER(ans),result,count*sizeof(double)); memcpy(&(NUMERIC_POINTER(ans)[count]),occur,count*sizeof(double)); /** PROTECT(dim=NEW_INTEGER(2)); INTEGER_POINTER(dim)[0]=2; INTEGER_POINTER(dim)[1]=count;

Dear ALL-R helpers, I want to let R get vector from c ,for example :numeric array ,vector .I saw some exmple like this : /* useCall3.c */ /* Getting an integer vector from C using .Call */ #include <R.h> #include <Rdefines.h> SEXP setInt() { SEXP myint; int *p_myint; int len = 5; PROTECT(myint = NEW_INTEGER(len)); // Allocating

Hi all, Could anyone point me to one or more examples in the R sources of a C function that is called without knowing in advance what will be the length (say) of the output vector? To make myself clearer, we have a C function that computes probabilities until their sum gets "close enough" to 1. Hence, the number of probabilities is not known in advance. I would like to have an

I have the following contrived code in package format. On Solaris and Mac OS X, code runs just fine. On Windows, it crashes the R environment with the "Send Bug Report" dialog. I tried R 1.8.1 (Win2K) and R 1.9 (WinXP) binaries with the same result. PCs otherwise appear properly configured for creating R packages. Anything blatantly wrong? Suggestions? TIA Relevant files from package

Dear R-developers, Using .Call I pass a S4 class with e.g. the following class definition: setClass("mmatrix",representation( data="matrix") ) On the "C side" i do mat = GET_SLOT(vs,install("data")); and then: printf("%f\n",NUMERIC_POINTER(mat)[1]); The above print statement produces the correct output if xx<- new("mmatrix")

Hi, Is there a way to resize a matrix defined as follows: SEXP a = PROTECT(allocMatrix(INTSXP, 10, 2)); int *pa = INTEGER(a) To row = 5 and col = 1 or do I have to allocate a second matrix "b" with pointer *pb and do a "for" loop to transfer the value of a to b? Thank you Best regards Morgan [[alternative HTML version deleted]]

Hello All, I recently upgraded from R-1.1.1 to R-1.2.2. I have an R function that uses .Call() to return a list from C code. The C code has the form: SEXP function(SEXP var) { SEXP rlist ; PROTECT(rlist = NEW_LIST(3)) ; VECTOR_PTR(rlist)[0] = NEW_INTEGER(1) ; VECTOR_PTR(rlist)[1] = NEW_STRING(1) ; ... UNPROTECT(1) ; return(rlist) ; } When I try to

I use a large real matrix, X, in C code that is passed from R and transposed in place in the C code. I would like to conserve memory and, if possible, allocate space for only one copy of X -- hence I would like to pass a pointer to the data in the X object to the C code. The Writing R Extensions manual says that neither .Call nor .External copy their arguments. They also say that these

Hello all, Is there a way to export C++ "unsigned" integer to R? (I am trying to parse files in "BPMAP" format, and some variables are of type unsigned int (first declared in C++) ). I know that to export signed integer to R, I can do the following in C++: int Some_INTEGER = 5; int *p_myInt; SEXP myInt; PROTECT(myInt=NEW_INTEGER(1)); myInt[0] = Some_INTEGER;

The subject line says it all. How can I find what Error: cannot set length of non-vector means? RTFS is no help. I can find out of course that it comes from "lengthgets", but who called that? Not me! The situation is as follows. I am trying to get a package ready for CRAN. Every time I run "R CMD check" I get this error when building the package vignette. But (!)

Hi, Trying to decrease the size of a SEXP variable without reassigning values individually in a loop. So far, I've tried using Realloc, as the follow source demonstrates: SEXP dothis() { SEXP Rblah; PROTECT(Rblah = NEW_INTEGER(6)); int* blah = INTEGER(Rblah); blah[0] = 1; blah[1] = 2; blah[2] = 3; Realloc(Rblah, 3, INTEGER); UNPROTECT(1); return(Rblah); } According to the

Matrix is just a vector with the dim attribute. Assuming it is not referenced by anyone, you can set any values to the dim attribute. As for the vector, you can use SET_LENGTH() to shorten it - but I'm not sure how official it is - it was originally designed to work, but there were abuses of TRUELENGTH so not sure where we stand now (shortened vectors used to fool the garbage collector as far

Hello: I was hoping to get some advice about how to return a tree (basically a linked list -- with each node containing a parent, left, and right node pointers) from a C routine back into R. Each node itself contains several attributes (a double, a char *, an int, and a void * ) Initially I was thinking I could just return to R a SEXP containing a pointer to the Root Node, but then realized

Hello, I create a VECSXP(call it A) with size N(~ 5000), i then proceed to fill the elements and find out I don't need to fill more than M (M<< N). Thus if i return A to the user's R code, he/she will see a list of length 5K of which N-M are NULLs. To avoid this, I create a new VECSXP B of length M and /duplicate/ the elements of A. Since I do this often, it appears to be wasteful,

There's a bit of an API glitch with Query objects at present. This code shows it off: Xapian::Database("/path/to/db"); Xapian::Enquire enquire(db); // make a simple query Xapian::Query myquery(Xapian::Query::OP_NEAR, phrase, phrase + 2); enquire.set_query(myquery); // Now change the query - this shouldn't affect the query enquire // will run, but it does.