similar to: Most elegant way to use formals() in building functions

With 0.63.3, try test <- function(){ fn <- function(a) print("hello") print(is.function(fn)) print(names(formals("fn")))} test() if fn is not quoted in the last line of test, it works properly. test <- function(){ fn <- function() print("hello") formals(fn) <- alist(a=,b=) return(fn)} formals(test()) now try with line 3 of test changed to

? Sat, 17 Feb 2024 11:15:43 -0700 "Reed A. Cartwright" <racartwright at gmail.com> ?????: > I'm wrapping a function in R and I want to record all the arguments > passed to it, including default values and missing values. This is hard if not impossible to implement for the general case because the default arguments are evaluated in the environment of the function as it

Hi, The R input/output after the following paragraph is from a session with version.string R version 2.4.0 Patched (2006-11-23 r39958). The last element, x$c, of x has no value and after the assignment of x to the formals of f, x$c does not become a formal argument of f. The second assignment does the job. It seems that x$c actually becomes the body of f after the first assignment. There is no

I'm proposing to signal an error (from R >= 3.3.0) in such examples -- which do "work" in R 3.2.x and earlier : > f <- NULL; body(f) <- quote(sin(a+1)); f function () sin(a + 1) <environment: 0x48f9798> > g <- NULL; formals(g) <- alist(x = pi, y=); g function (x = pi, y) NULL <environment: 0x4e6dfe8> > The proposal is that the underlying C

Dear list, I have the following function, sugar = function(fun, id = "id"){ ff <- formals(fun) if( id %in% names(ff)) stop("id is part of args(fun)") formals(fun) <- c(unlist(ff), alist(id=)) fun } which one may use on a function foo, foo = function(x){ x } sugar(foo) # results in the extended closure, function (x, id) { x } Its limitation (other

I think this is new since a previous version of R: > h <- function(x, trantab) trantab[x] > w <- 6:4 > names(w) <- c('cat','dog','giraffe') > w cat dog giraffe 6 5 4 > > formals(h) <- list(x=numeric(0), trantab=w) > h function (x = numeric(0), trantab = c(6, 5, 4)) trantab[x] You can see that the names

Hi all, What's the official name for the value that represents a missing argument? e.g. formals(plot)$x str(formals(plot)$x) deparse(formals(plot)$x) is.symbol(formals(plot)$x) What's the correct way to create an object like this? (for example if you are manipulating the formals of a function to add an argument with no default value, as in http://stackoverflow.com/questions/3892580/).

Dear list # I have a function ff <- function(a,b=2,c=4){a+b+c} # which I programmatically want to modify to a more specialized function in which a is replaced by 1 ff1 <- function(b=2,c=4){1+b+c} # I do as follows: vals <- list(a=1) (expr1 <- as.expression(body(ff))) expression({ a + b + c }) (expr2 <- do.call("substitute", list(expr1[[1]], vals))) { 1 +

_________________________________________________________________________= ______________ Note: This e-mail is subject to the disclaimer contained at the bottom of= =20this message. _________________________________________________________________________= ______________ Just a note on the reported bug; it seems to be related to having a NULL function body. # this works > f <-

I've added a "backsolve" method to the bdsmatrix library. Per the Extending manual section 7.1 I've also added the following 3 lines along with my setMethod definitions for 2 classes. backsolve <- function(r, ...) UseMethod("backsolve") backsolve.default <- base:::backsolve formals(backsolve.default) <- c(formals(backsolve.default), alist(... = )) I've

I'd like to report two bugs in the R function definitions, the first slightly problematic, the second likely unimportant. Both of these are reproducible on both Windows and Linux, R 2.0.1 First Bug: > a <- new("function") > formals(a) <- alist(a=, b=, c=, d=) > a function (a, b, c) ## the d argument disappeared! > formals(a) <- alist(a=, b=, c=, d=) > a

On Sat, Oct 15, 2016 at 2:00 AM, Martin Maechler <maechler at stat.math.ethz.ch> wrote: >>>>>> Michael Lawrence <lawrence.michael at gene.com> >>>>>> on Wed, 12 Oct 2016 15:21:13 -0700 writes: > > > Thanks, this was what I expected. There is a desire to > > eliminate the usage of pairlist from user code, which > >

Dear list I have a function and a vector, say f <- function(a,b){a+b} x <- c(2,3) I want to "evaluate f on x" in the sense of computing f(x[1],x[2]). I would like it to be so that I can write f(x). (I know I can write a wrapper function g <- function(x){f(x[1],x[2])}, but this is not really what I am looking for). Is there a general way doing this (programmatically)?

Hi, I am a little bit surprised by the following output of 'formals'. Is this the intended behavior? > f <- function(a=1,b=-1) { a+b } > class(formals(f)$a) [1] "numeric" > class(formals(f)$b) [1] "call" Josef -- ----------------------------------------------------------------------------- Josef Leydold | WU (Vienna University of Economics and

Hi, On 03/07/2016 09:26 AM, Martin Maechler wrote: > I'm proposing to signal an error (from R >= 3.3.0) in such > examples -- which do "work" in R 3.2.x and earlier : > >> f <- NULL; body(f) <- quote(sin(a+1)); f > function () > sin(a + 1) > <environment: 0x48f9798> > This works because formals() (the getter) works on things that are not a

Hello R useRs, I have a function which returns a list of functions : freq1 <- function(x) { lev <- unique(x[!is.na(x)]) nlev <- length(lev) args <- alist(x=) if (nlev == 1) { body <- c("{", "sum(!is.na(x))", "}") f <- function() {} formals(f) <- as.pairlist(args) body(f) <- parse(text = body) namef <-

Is there a way of getting the argument list of a function from within that function? For example, something like f <- function(x, y = 3) { fargs <- getFunctionArgList() print(fargs) ## Should be `alist(x, y = 3)' } Thanks, -roger

This is tangentially related to Hadley's question. Suppose I'm building a function programmatically; I have assembled an expression for the body and I know the names of the arguments it wants to take. Suppose I have some convenience function such that writing make_function(alist(a=, b=), quote(a+b), environment()) is equivalent to writing function(a,b) a+b So how do I make the

Hi, Thanks for the note. How would explain the following snippet taken from `formals` doc page (the code comment is also from that doc) ? ## formals returns NULL for primitive functions. Use it in combination with ## args for this case. is.primitive(`+`) formals(`+`) formals(args(`+`)) Le sam. 6 oct. 2018 ? 13:42, Rui Barradas <ruipbarradas at sapo.pt> a ?crit :

Full_Name: Jörg Polzehl Version: 1.8.0 OS: Windows XP Submission from: (NULL) (62.141.176.1) I encountered a problem when playing with the mle library and specifying negative starting values for the parameters. The reason seems to be an incorrect behaviour of function formals: glike<-function(a=1,b=1,c=1) a > formals(glike) $a [1] 1 $b [1] 1 $c [1] 1 > unlist(formals(glike)) a b c