similar to: dyn.unload fails after some C++ code.

Hi, I am trying to modify the devX11.c source in the directory R-2.4.1/ src/modules/X11. Under OS X 10.4.9 running the R gui (R version 2.4.1) on a Powerbook, i type this and get the subsequent error. > dyn.unload("/Library/Frameworks/R.framework/Resources/modules/ppc/ R_X11.so") Error in dyn.unload(x) : dynamic/shared library '/Library/Frameworks/

Hi, I am writing C++ functions that are to be called via .Call() interface. I'd been using error() (from R.h) to return to R if there is an error, but then I realized that this might be not safe as supposedly error() doesn't throw an exception and therefore some destructors do not get called and some memory may leak. Here is a simple example extern "C" void foo() { string

Hello: I am having some difficulty with a DLL, using > version _ platform i386-pc-mingw32 arch x86 os Win32 system x86, Win32 status major 1 minor 2.1 year 2001 month 01 day 15 language R I have a library called

Dear R-Users, I am reading the "An Introduction to R" manual and have come across data() function for loading data. I assume that R requires explicit loading of data objects to save memory. Then I'd expect there should be a function that can unload the objects once they are not needed anymore, what is this function? It would be helpful if ?data contained a reference to that

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 >

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, 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, 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, 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

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

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]]

Good question Rolf. Rui, thanks for pointing out dyn.unload. When I started using Rcpp a couple of years ago I got burned by stale .so enough times that I adopted a policy of recompile-then-start new R session. My workflow does not include Rolf's "brazillion" repeats, so the overhead of this approach has not been too painful. The documentation for dyn.unload (via ?dyn.unload)

After having browsed the documentation for a while without discovering what I am looking for, maybe one of you would know ... What I want to do: I have two fortran files MC.f and ESCA.f. In MC.f there is a call to a routine called lpost. This routine (lpost) is defined (among other things) in ESCA.f. Under linux, I can do the following: R CMD SHLIB MC.f and R CMD SHLIB ESCA.f followed by

Hello, In such cases, with C code, I call dyn.unload before loading the modified shared lib again. I don't know if this changed recently, but it used to be needed or else R wouldn't load the new lib. When I call dyn.unload followed by dyn.load I never had problems. (Or the other way around, call dyn.unload before modifying the C code.) Hope this helps, Rui Barradas On 3/1/2018 8:52

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

I sent this enquiry to r-help and received several sympathetic replies, none of which were definitive. It was kindly suggested to me that I might get better mileage out of r-devel, so I'm trying here. I hope that this is not inappropriate. My original enquiry to r-help: ========================================================================== I am working with a function "foo"

Sorry, forgot to send this to the list originally. -----Original Message----- From: Mike Waters [mailto:dr.mike at ntlworld.com] Sent: 06 May 2005 18:40 To: 'Campbell' Subject: RE: [R] distance between distributions -----Original Message----- From: r-help-bounces at stat.math.ethz.ch [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Campbell Sent: 06 May 2005 11:19 To:

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, As far as I can tell data.frame class adds two features to those of lists: * matrix structure via [,] and [,]<- operators (well, I know these are actually "["(i, j, ...), not "[,]"). * row names attribute. It seems that the overhead of the support for the row names, both computational and RAM-wise, is rather non-trivial. I frequently subscript from a data.frame,

>From Hadley's C best practices (http://r-pkgs.had.co.nz/src.html#c-best-practices): > Like with C++, whenever you use C code in your package, you should unload the DLL when the package is unloaded: .onUnload <- function (libpath) { library.dynam.unload("mypackage", libpath) } Writing R Extensions on the other hand doesn't even mention this (AFAIK). I