similar to: How allocate STRSXP outside of gc

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, 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 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

Dear list, I am trying to implement a publish-subscribe mechanism in for an embedded R interpreter. But somehow my registered closures seem to get collected by the GC, even though I have protected them. I have reducted my code to the following sample. Sorry if it is a little verbose. The first couple of call of calls still work, but at some point one of the callbacks (callback1 in my

I am occasional getting "Segmentation Fault - core dumped" in R 0.62.3 (I think more often then I did in 0.62.2). I have not been able to do this in any reliably reproducible way yet, but thought I would mention the problem in case some else can isolate it. Paul Gilbert -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read

This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_000_01C3738F.63DE3390 Content-Type: text/plain; charset="iso-8859-1" #I want to be able to create a new S4 class and read data into it using C code # Here is a very simple S4 object inheriting from "array", but with 5

Hi, I have been studying the R manual on lists but cannot seem to create a simple R list in C - I keep on getting "'dimnames' applied to non-array" whenever I attempt to assign names to the list elements: Wanted output a list structure something like [ type="Bid", price=2.0, volume=1000 ] I can get up to a list of [ "Bid2, 2.0, 1000 ] But for the life of

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 all, I am working with some large data sets (1-4 GB) and have some questions that I hope someone can help me with: 1. Is there a way to turn off garbage collector from within C interface ? what I am trying to do is suck data from mysql (using my own C functions) and I see that allocating each column (with about 1-4 million items) takes between 0.5 and 1 seconds. My

Hi, This is not an R question per ce, but I feel like this is a right community to ask it. As a part of our work we run a lot of non-interactive computational jobs. To increase the throughput we would like to distribute the load over the entire network and we are looking at Linux network as a platform. Ideally we would like to be able to submit a job to the network, rather than to a computer, and

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]]

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 trying to create a dataframe in C and sebd it back to R. Can anyone point me to the part of the source code where it is doing , let me explain the problem I am having . -------------------------------------------------------------------- My simple implementation is like this SEXP formDF() { SEXP dfm ,df , dfint , dfStr,lsnm; char *ab[3] =

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 am having a problem to understand why as.data.frame method doesn't dispatch properly on my class: > setClass("Foo", "character") [1] "Foo" > as.data.frame(list(foo=new("Foo", .Data="a"))) Error in as.data.frame.default(x[[i]], optional = TRUE) : can't coerce Foo into a data.frame I was expecting that this would call

The documentation for the POSIXlt class states '"POSIXlt" objects will often have an attribute "tzone", a character vector of length 3 giving the time zone name from the TZ environment variable and the names of the base time zone and the alternate (daylight-saving) time zone. Sometimes this may just be of length one, giving the time zone

I'm very green with R, so maybe this is not a bug, but it looks like one to me. The following program segfaults at the second call to Rf_PrintValue(). To failure depends on the value of the y-string. E.g., if I change it from "coverage" to, say, "COVERAGE", the segfault does not occur. /* bug.c */ #include <stdio.h> #include <Rinternals.h> #include

Hi guys, I've got a question about the API mkchar(). I have met some difficulty in parsing utf-8 string to mkchar() in R-2.7.0. I was intending to parse an utf-8 string str_jan (some Japanese characters such as?, whose utf-8 code is E381B5) to R API SEXP mkChar(const char *name) , we only need to create the SEXP using the string that we parsed. Unfortunately, I found when parsing the

Dear R Folks, I'm a big fan of R, but there are a couple of things that repeatedly annoy me, and I wondered if anyone has neat ways to deal with them. (a) When using "apply" row-wise to a matrix, it returns the results column-wise, and to preserve the original orientation, I've to do a transpose. E.g. I've to keep doing a transpose, which I consider to be quite