search for: findvar

Hi All, I have a few small questions about the usage of the C findVar( ) function when used in C code called with '.Call'. In my case I create an R function with an argument. This function calls some C code in which I use findVar( ) to retrieve the values from the argument. Ofcourse normally I would just give the values as argument to .Call, but in my project...

Hello. In the writing of my OCaml-R binding, I'm sort of confused when it comes to the use of the PROTECT and UNPROTECT macros. Basically, I have C stub functions that are in charge of calling R for everything. Here's a simple example: > CAMLprim value r_findvar (value symbol) { > /* The findVar function is defined in envir.c. It looks up a symbol > in an environment. */ > CAMLparam1(symbol); > CAMLreturn(Val_sexp(findVar(Sexp_val(symbol), R_GlobalEnv))); > } This simply makes a call to findVar and returns the value to Objective...

Dear all, when working on a project with embedded R, I found out that R-2.0.0 causes a problem where older versions worked OK. Rf_findVar(...) causes the following error when used to find a generic function (such as print): fun = Rf_findVar(...); R_tryEval(fun, ...); Error in function (object, ...) : Invalid generic function in usemethod Alternatively, using Rf_findFun(...) seems OK in this context, but crashes if you call it wit...

Dear list, I have been using "findVar" (defined in src/main/envir.c) happily and would like to use "findFun". However I have trouble when the name searched cannot be found: while "findVar" returns R_UnboundValue, "findFun" does not (the 4 last lines of "findFun" are copied below). erro...

...ecause only fonts numbered 1..5 are actually defined. I don't know how to fix it. 2. The ?postscript help topic refers to .ps.profile; the actual variable name is .ps.prolog. The C source in main/devPS.c has this on lines 606-608, with the incorrect name in the error message: prolog = findVar(install(".ps.prolog"), R_GlobalEnv); if(!isString(prolog)) error("Object .ps.profile is not a character vector"); 3. And this is a suggestion, not a bug: I'd like to change the font definitions by changing the .ps.prolog instructions, but devPS.c puts the...

Full_Name: Ben K. Version: 1.7.1 OS: Win 2000 Submission from: (NULL) (208.243.20.222) This C code doesn't crash: void init(SEXP rho, int *o){ SEXP vars = findVar(install("vars"), rho); } It's called using: vars <-as.data.frame(NULL) vars$delta <-7 dyn.load("c_fns.dll") print(.C("init",.GlobalEnv,o=as.integer(3))$o) However, this does crash (``Rgui has generated errors and will be closed by Windows'...

...ignore it and return the cdr with all its expressions evaluated; * if it is bound to a ... list of promises, * we force all the promises and then splice * the list of resulting values into the return value. * Anything else bound to a ... symbol is an error */ h = findVar(CAR(el), rho); if (TYPEOF(h) == DOTSXP || h == R_NilValue) { while (h != R_NilValue) { if (mode==1) { PROTECT(head); mode = 2; } ev = CONS(eval(CAR(h), rho), R_NilValue);...

...o I end up with a lot of symbols in the rho environment. The problems I've seen are hard to reproduce: sometimes it's a segfault, sometimes a "cons memory exhausted" error, or sometimes everything looks fine except that, later, when I retrieve values from the rho environment with findVar(), some of them are altered! But if I replace the above line by: PROTECT(ans = mkans(x)); defineVar(install(somekey), ans, rho); UNPROTECT(1); then everything works fine :-) Cheers, H.

...y C++ code. I am facing an error while executing more than 1 R-expressions parallelly. I am executing round(X) and abs(X) parallelly on a set of 50 input rows which resulted in segmentation fault after getting the following errors. Error: unprotect_ptr: pointer not found Error: argument to 'findVar' is not an environment I am using the following code snippet for initializing R, parsing and evaluation of R expression // For initialization int res= Rf_initEmbeddedR(R_argc, (char**)R_argv); // For parsing and evaluation SEXP cmd1= Rf_mkChar(rscript); SEXP cmdSexp, cmdex...

I'm a day-old R newbie (but a war-weary S veteran), with couple of first-day questions: In R 0.61, this code fails. Ops.test <- function(e1,e2) { e1 <- NextMethod(.Generic) e1 } x <- 4 class(x) <- "test" y <- x < 3 The error message is "Error in NextMethod(.Generic) : negative length vectors are not allowed.". I assume it is a bug.

...earch from as I think we need to avoid mycoef <- function(x) { mycoef <- function(x) stop("not this one") UseMethod("mycoef") } so I used ENCLOS(env). This adds some overhead, hopefully no more than searching for methods. BTW, I noticed that R_LookupMethod uses findVar, that is looks for any object not for functions: that must be another infelicity. -- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road,...

...ion. I have tried to look for one but until now without success. My question is: can you see a design flaw here or is everything done according to R requirements and hence it is likely that there is a bug in my own code? One dirty correction I can see but have not tried is to use object names and findVar but this would make it less flexible (at least IMHO). I have quickly browsed the forums and the documentation I was able to find but found no answers. My system is FC3 with R version >= 2. There are two snippets of code that hopefully make clear what I am trying to achieve. The code is provid...

...{ ans <- callNextMethod() ans@nrow <- nrow(ans@df) ans }) b <- new("B", df=mtcars) dropLowMpg(b) Error in eval(expr, envir, enclos) (from #3) : object 'cutoff' not found We can fix this with a simple C function: SEXP top_prenv(SEXP nm, SEXP env) { SEXP promise = findVar(nm, env); while(TYPEOF(promise) == PROMSXP) { env = PRENV(promise); promise = PREXPR(promise); } return env; } With R wrapper: top_prenv <- function(x) { .Call2("top_prenv", substitute(x), parent.frame()) } Then this works (need to set subset,B again to reset cache):...

...===================================================== --- src/main/gevents.c (revision 71293) +++ src/main/gevents.c (working copy) @@ -211,8 +211,6 @@ int i; SEXP handler, bvec, sx, sy, temp, result; - dd->gettingEvent = FALSE; /* avoid recursive calls */ - PROTECT(handler = findVar(install(mouseHandlers[event]), dd->eventEnv)); if (TYPEOF(handler) == PROMSXP) { handler = eval(handler, dd->eventEnv); @@ -242,7 +240,7 @@ R_FlushConsole(); } UNPROTECT(1); /* handler */ - dd->gettingEvent = TRUE; + return; } @@ -257,8 +255,6 @@ { SEXP...

...v. Can anyone tell me why? [ My motivation is that I want use defineVar to initialise a workingEnvironment (corresponding to Value below), so that event-handler functions for a specific C library (which must have a specific prototype) can call R functions by looking up workingEnvironment with findVar. Earlier, I tried a static global SEXP variable in C to keep track of the environment, but that's not reliable because of garbage collection. Maybe SEXPREC would work better? ] Thanks in advance, James ***** testR_GlobalEnv.c ***** #include <R.h> #include <Rinternals.h> #includ...

...ys.function has to grab the call, take the 1st element, and reevaluate it in the parent frame. It is quite easy to think up examples where a second evaluation does not give the same value as the first. Your particular case is of a slightly different natur and should be easily fixable by replacing findVar in R_sysfunction by findVar1 and looking specifically for objects of mode "function", but the basic problem persists. I don't think I want to risk fixing this (and maybe unfixing something else) for 1.2.3 tomorrow though. -- O__ ---- Peter Dalgaard Blegdamsvej 3...

...n coerce.c : Thanks, I was just coming to the same conclusion. I'll look into it. Duncan > > ---------------------------------------------------------------------------- > r37269 | murdoch | 2006-02-05 18:00:54 +0100 (Sun, 05 Feb 2006) | 7 lines > > Changes to substitute and findVar: > In C, substitute( , R_NilValue) does no substs, just > getting PREXPRs, while substitute( , R_GlobalEnv) does > substitutions. > > In R: substitute( , .GlobalEnv) is just like > R_NilValue above, as is substitute( , NULL). > ------------------------------------------------...

...around and finds the data to an R variable name: SEXP getVar(SEXP name, SEXP rho) { SEXP ans; if(!isString(name) || length(name) != 1) error("name is not a single string"); if(!isEnvironment(rho)) error("rho should be an environment"); ans = findVar(install(CHAR(STRING_ELT(name, 0))), rho); return ans; } To get the data of an R-variable you should be able to use the constructors from Rcpp that take an SEXP as argument, but i also haven't tried that yet. What I found to be useful too is the routine for evaluating R-commands:...

...ef WITH_LINENO { 0, VSTRFIXED|VTEXTFIXED, linenovar, 0 }, +#endif #ifndef SMALL { 0, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM\0", 0 }, { 0, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE\0", sethistsize }, @@ -335,9 +337,11 @@ lookupvar(const char *name) struct var *v; if ((v = *findvar(hashvar(name), name)) && !(v->flags & VUNSET)) { +#ifdef WITH_LINENO if (v == &vlineno && v->text == linenovar) { fmtstr(linenovar+7, sizeof(linenovar)-7, "%d", lineno); } +#endif return strchrnul(v->text, '=') + 1; } return NULL;...

1. Is there some way to copy a promise so that the copy has the same expression in its promise as the original. In the following we y is a promise that we want to copy to z. We want z to be a promise based on the expression x since y is a promise based on the expression x. Thus the answer to the code below is desired to be z=2 but its 1, 1 and y in the next three examples so they are not the