similar to: Evaluate part of an expression at C level

Dear R-help, how could I create an R call in C code using lang2 with 2 and more arguments? I tried this code: SEXP f(SEXP fn, SEXP rho) { SEXP R_fcall, x, y; PROTECT(R_fcall = lang2(fn, R_NilValue)); PROTECT(x = allocVector(REALSXP, 1)); PROTECT(y = allocVector(REALSXP, 1)); REAL(x)[0] = 10; REAL(y)[0] = 20; SETCADR(R_fcall, x); SETCADR(R_fcall, y);

Hi everyone, I am starting learn to call C code from within R. So far, I've been trying toy problems to see if I can get them to work. One of the things I'd like to do is pass an arbitrary R function to C, evaluate the value in the C code using eval, and then return it. I also want to allow an arbitrary number of arguments to the function using "...". The code for my toy

Hi, I'm writing a C function that has to call a R function with multiple arguments. I've read the relevant section in Writing R Extensions, and searched the R site, mailing lists as well as rseek. I managed to call the function, but I'm now having trouble creating the argument list. I tried to create a pairlist of the arguments and send it to the R function. The R function however

I'm preparing some code to compute the optimal geometry of stressed solids. The core of the calculations is the optimization of elastic energy using the simulated annealing method implemented in the R optim() rutine. I've defined a function to compute this "energy" scalar (the fn parameter for optim) and prepared a list with the arrays defining the geometry and the elastic

Hi R-Developers, I'm working on running statistical analyses with embedded R from a Qt-GUI-application (C++). I've been able to link with R libraries, but I'm having a hard time to understand the C-coding examples. I'm a C++, not a C programmer (never used malloc before), and many of the R-specific functions/keywords/macros (for instance (UN)PROTECT, SETCAR, all the

Hi folks, I apologise if this is in the documentation somewhere, but I can't seem to find it. I also did a search of CRAN without any success. I'm using R-1.8.1 (pre-compiled) on Windows 2000 with Rtools and mingw 2.0.0 (which includes gcc/g++ 3.2). I'm trying to link some C++ code from another application to R using the .Call interface and am experiencing some problems. I was

Dear All, I've read the manual on "Writing R Extensions" and in particular the part on calling R from C. (Most of the manual is about calling C from R, not the other way around.) The good news is that I can now call _some_ R from C, specifically the R functions which have C header files. However it isn't clear to me how to call R functions that are written in R. I

Dear list-subscriber, in the process of writing a general code snippet to extract coefficients in an expression (in the example below: 0.5 and -0.7), I stumbled over the following peculiar (at least peculiar to me:-) ) sorting behaviour of the function all.names(): > expr1 <- expression(x3 = 0.5 * x1 - 0.7 * x2) > all.names(expr1) [1] "-" "*" "x1"

I think you are confusing package and function here. Plus some of the R Core packages, that you mention, contain functions that should probably be replaced by functions with better implementation from packages on CRAN. Best regards Morgan On Fri, 11 Oct 2019 15:22 Joris Meys, <jorismeys at gmail.com> wrote: > > > On Fri, Oct 11, 2019 at 3:55 PM Morgan Morgan <morgan.emailbox

How do you prove usefulness of a feature? Do you have an example of a feature that has been added after proving to be useful in the package space first? Thank you, Morgan On Fri, 11 Oct 2019 13:53 Michael Lawrence, <lawrence.michael at gene.com> wrote: > Thanks for this interesting suggestion, Morgan. While there is no strict > criteria for base R inclusion, one criterion relevant

Dear R-users, Suppose I have an expression: expr = expression(a>0) and now I want to modify it to expression(a>0 & b>0). The following doesn't work: expr = expression(expr & b>0) What would be a good way of doing this? Thanks, Vadim ________________________________ Note: This email is for the confidential use of the named addressee(s) only and may contain

Hi, I am using R a lot to make plots relating to radioactivity, I am often using expression() to label the plots with nuclide names written with superscripts, e.g. expression(paste("Releases of ", { }^{99},Tc," (TBq/year)"))->ywtext But, is there any simple way to change the number and name of the nuclide through a variable? I tried nuccode=expression({ }^{99},Tc)

Hello! I work with: R : Copyright 2006, The R Foundation for Statistical Computing Version 2.3.1 (2006-06-01) On Windows XP Professional (Version 2002) SP2 I think there is a bug in the conditional execution if (expr1) {expr2} else {expr3} If I try: "if (expr1) expr2 else expr3" it works well but when I put the expression expr2 and expr3 between {} I receive an error message

hi, is this a feature or a bug in conjunction with apple mail. i usually use the feature in imap to not delete the emails, but only mark them as deleted, which is a very usefull feature if you use a emailbox with more people accessing it. Im now trying an SME server installation with dovecot 0.99.10, and when i delete a message, it gets marked as deletet, but as soon as i change the mailbox

Hi, Is there any equivalent for ifelse (except if (cond) expr1 else expr2) which takes an atomic element as argument but returns vector since ifelse returns an object of the same length as its argument? x = c(1,2,3) y = c(4,5,6,7) z = 3 ifelse(z <= 3,x,y) would return x and not 1 thanks

Dear R-helpers I have a problem related to the use of NLME I think is simply a matter of getting the nlme coding correct, but i cannot get my brain around it I am analysing some 24 growth curves of some cells , and i wanted to say that there are significant differences between the curves in two parameters that describe the pattern of growth. these parameters are from a logistic (r & k)

I have a situation where this is fine: > if (length(x)>15) { clever <- rr.ATM(x, maxtrim=7) } else { clever <- rr.ATM(x) } > clever $ATM [1] 1848.929 $sigma [1] 1.613415 $trim [1] 0 $lo [1] 1845.714 $hi [1] 1852.143 But this variant, using ifelse(), breaks: > clever <- ifelse(length(x)>15, rr.ATM(x, maxtrim=7), rr.ATM(x))

This may have been asked before, but is there an elegant way to check whether an variable/argument passed to a function is a "parse tree" for an (unevaluated) expression or not, *without* evaluating it if not? Currently, I do various rather ad hoc eval()+substitute() tricks for this that most likely only work under certain circumstances. Ideally, I'm looking for a isParseTree()

Using an example provided by "The Hitchhiker's Guide to Asterisk", I made the following addition to my extensions.conf file: [inbound-analog] exten => s,1,Wait(1) exten => s,2,SetVar(counter=0) exten => s,3,Answer() exten => s,4,Wait(1) exten => s,5,DigitTimeout(15) exten => s,6,ResponseTimeout(10)

Hello! I have the following problem: I have a function to construct three surfaceplots with a marker for an optimum, each of the plots has as title paste("Estimated ",pred.var.lab," for ",var.lab[1]," vs. ",var.lab[2],sep="") with different var.lab[1,2] each time. My problem is now that I need to allow for plotmath expressions in the variables pred.var.lab