similar to: memory allocation and interrupts

Hi, As was discussed earlier in another thread and as documented in R-exts .Call() should not be interruptible by Ctrl-C. However the following code, which spends most of its time inside mkChar, turned out to be interruptible on RH-7.3 R-1.8.1 gcc-2.96: #include <Rinternals.h> #include <R.h> SEXP foo0(const SEXP nSexp) { int i, n; SEXP resSexp; if (!isInteger(nSexp))

I believe IO in R is slow because of the way it is implemented, not because it has to do some extra work for the user. I compared scan() with 'what' argument set (which is, AFAIK, is the fastest way to read a CSV file) to an equivalent C code. It turned out to be 20 - 50 times slower. I can see at least two main reasons why R's IO is so slow (I didn't profile this though): A) it

Hi, Somehow function-like macros from Rinternals.h are not defined when I include the file. foo.c ################## #include <R.h> #include <Rinternals.h> #ifndef NILSXP #error("NILSXP") #endif #ifndef INTEGER #error("INTEGER") #endif ################### When compiled: vor/src% gcc -I/usr/local/lib/R/include -g -O2 -c foo.c -o foo.o foo.c:11:2: #error

Hi all, im triyng to implement a bayesian model with R and c++. I have a strange problem. I can't reproduce the error with a small script and then i post the original one. The problem is after the line for(MCMC_iter2=0;MCMC_iter2<thin;MCMC_iter2++) For the first 34 iterations all work fine, after, all the simulations of mu_acc_P return an "nan". If i delete the line

Hi, Could someone please point to an example of passing strings from .C() calls back to R? I want to be able to do something like this: str <- .C("return_foo_string", str=character(1))$str void return_foo_string(char ** str) { *str = "foo"; } The above code has at least two memory allocation "concerns": 1) How to properly allocate "foo". I

Hi, I'm using dyn.load to load a shared library (compiled from C code) into R. If I dyn.unload it and then dyn.load it again, I get an hourglass icon in Rgui (R 1.7.0, Win 2000), and it just sits there forever. I can't press Escape to stop the current computation, but I can close Rgui without resorting to using the Task Manager. Is it a problem with my use of R_alloc? Do I need

Dear R-devel, Some time ago I started a thread that boiled down to clean-up actions after non-local exits in R, see below. I wonder if there has been any progress on this? R-ext 2.6.1 doesn't say much on the subject. How, for example, do people deal with a situation where their C (C++) function opens a file and then receives a signal or longjump-s on error(), how do they make sure the

Hi, Is it possible to modify an object in the parent.env (as opposed to re-bind)? Here is what I tried: > x = 1:3 # try to modify the first element of x from within a new environment > local(get("x", parent.env(environment()))[1] <- NA) Error in eval(expr, envir, enclos) : Target of assignment expands to non-language object # On the other hand retrieval works just fine >

I want to write a little stand-alone C program that calls R_alloc, but I get a segmentation fault: int main(int argc, char** argv){ double* d = (double *)R_alloc(2, sizeof(double)); // <- segmentation fault! return 0; } gdb reveals that sizeof(double) evaluated to 0: > R_alloc (nelem=2, eltsize=0) at memory.c:1649 so it results in the segfault later. This is how I compile my

Hi, I am looking for an efficient way of skipping big chunks of lines on a connection (not necessarily at the beginning of the file). One way is to use read lines, e.g. readLines(1e6), but a) this incurs the overhead of construction of the return char vector and b) has a (fairly remote) potential to blow up the memory. Another way would be to use scan(), e.g. scan(con, skip=1e6, nmax=0)

Hi, I thought it would be convenient if the check.names argument to read.table, which currently can only be TRUE/FALSE, could take a function value as well. If the function is supplied it should be used instead of the default make.names. Here is an example where it can come in handy. I tend to keep my data in coma-separated files with a header line. The header line is prefixed with a comment

Hi, What is the reason for seq.Date to require the 'by' argument and not to default it to 1 in the example below? > seq(from=as.Date("1996-01-01"), to=as.Date("1996-12-01")) Error in seq.Date(from = as.Date("1996-01-01"), to = as.Date("1996-12-01")) : exactly two of `to', `by' and `length.out' / `along.with' must be specified

Hi, To speed up reading of large (few million lines) CSV files I am writing custom read functions (in C). By timing various approaches I figured out that one of the bottlenecks in reading character fields is the mkChar() function which on each call incurs a lot of garbage-collection-related overhead. I wonder if there is a "vectorized" version of mkChar, say mkChar2(char **, int

Dear All, In a package, I want to use some C code where I am using a structure (as the basic element of a linked list) with flexible array members. Basically, this is a structure where the last component is an incomplete array type (e.g., Harbison & Steel, "C, a reference manual, 5th ed.", p. 159) such as: struct Sequence { struct Sequence *next; int len; unsigned int

I have some compiled code that works under winXp but not under linux (kernel 2.6.10-5). I'm also using R 2.1.0 After debugging, I've discovered that in this code: #define NMAX 256 long **box; ... box = (long **)R_alloc(NMAX, sizeof(long *)); //<---HERE THE SIGSEGV for (i=0; i<NMAX; i++) box[i] = (long *) R_alloc(NMAX, sizeof(long)); inside the *first* call to the

Hi, It seems that a formal function argument can not default to an "outer" variable of the same name: > x <- "foo" > ff <- function(x=x) x > ff() Error in ff() : recursive default argument reference > Is this intentional? Why? I use R-1.9.1. Thanks, Vadim

Full_Name: Wolfgang Huber Version: R-devel_2005-03-10 OS: alphaev68-dec-osf4.0f Submission from: (NULL) (62.253.128.15) This report concerns allocation of large (>2^31 byte) chunks of memory with R_alloc. I suspect it is a bug/typo but please don't hate me if it's actually a feature: In R, I can happily create large matrices: > a= matrix(0, nrow=191481, ncol=3063) > dim(a) [1]

Hi, I tried to write the dim method for the list class, but R doesn't seem to dispatch to it: > dim.list = function(x) c(length(x[[1]]), length(x)) > dim(list(1)) NULL > dim.list(list(1)) [1] 1 1 What is the correct way of registering dim.list with .Primitive("dim")? Thanks, Vadim [[alternative HTML version deleted]]

I have some compiled code that works under winXp but not under linux (kernel 2.6.10-5). I'm also using R 2.1.0 After debugging, I've discovered that this code: #define NMAX 256 long **box; ... box = (long **)R_alloc(NMAX, sizeof(long *)); gives a null pointer, so subsequent line: for (i=0; i<NMAX; i++) box[i] = (long *) R_alloc(NMAX, sizeof(long)); gives a SIGSEGV signal.

WRE explains that R_alloc() can be used to allocate memory which automatically gets released by R at the end of a .C, .Call or .External, even in the case of an error or interruption. This is a really great feature to prevent memory leaks. I was wondering if there is a way to extend this mechanism to allow for automatically running UNPROTECT and custom finalizers at the end of a .Call as well.