similar to: Parser For Line Number Tracing

Hi Ivo, I maintain 'package:this.path' that I believe does what you want. I regularly add this to my own code when I need to: warning(sprintf("remove this later at %s#%d", this.path::try.this.path(), this.path::LINENO()), call. = FALSE, immediate. = TRUE) Of course, modify as needed. Regards, Iris On Sat, Jan 18, 2025 at 6:41?PM Ivo Welch <ivo.welch at gmail.com>

On 2025-01-18 6:41 p.m., Ivo Welch wrote: > I often find myself hunting where in my program an error has happened, > (of course, in R, many error messages are mysterious in themselves, > too, making it even harder.) the way I do it is mostly with inserting > `message()` statements. > > what I would really like to have is a parser that inserted 'curline > <<-

Hi Duncan ? Wonderful. Thank you. Bug or no bug, I think it would be a huge improvement for user-friendliness if R printed the last line by default *every time* a script dies. Most computer languages do so. Should I file it as a request for improvement to the R code development team? Maybe R can be improved at a very low cost to the development team and a very high benefit to newbies.

On Sun, 19 Jan 2025, Ivo Welch wrote: > Hi Duncan ? Wonderful. Thank you. Bug or no bug, I think it would be > a huge improvement for user-friendliness if R printed the last line by > default *every time* a script dies. Most computer languages do so. > > Should I file it as a request for improvement to the R code > development team? Maybe R can be improved at a very low cost

Thanks for pointing out the options. Using options(show.error.locations = TRUE) works on Ivo's example, but it doesn't show a location if the error happens in a function that doesn't have srcrefs, because the known location isn't on the top of the stack. Perhaps TRUE (and maybe "top"?) should look back through the stack until it finds a known location, and

I've posted a patch to bugs.r-project.org that fixes the traceback() issue. It's not specific to findFun3; you get the same problem with errors from expressions like 1 + "a" In my testing, I occasionally saw cases where show.error.locations = TRUE didn't work. I'll try to track down a reproducible case, and perhaps a patch to fix it. Duncan Murdoch On

understood. but, please, consider not people like me but unwary beginners and students of R. I have used R now for decades, and even I am baffled by it. Couldn't you make R code easier to debug not only for people like me (who can indeed tweak their environments) but also for novice users? On Sun, Jan 19, 2025 at 8:46?AM <luke-tierney at uiowa.edu> wrote: > > On Sun, 19 Jan

Avi, Yes, R (really S) was not designed for novice users but rather for experts. For better or worse it has evolved into a programming language used by tyros, and experts. Debugging tools should be easy to use, generally known, and helpful for tyro and expert. It would certainly help if R reported the line number, or the code, that generated the error. John John David Sorkin M.D., Ph.D.

Sorry, I'm not seeing the first problem now: options(show.error.locations = TRUE) works fine. Not sure what I did wrong before. I'm still seeing `traceback()` failing to report the attempt to call nofunction(). I suppose this is because a context is never set up for the failed call. Perhaps findFun3 could set up a fake context so that traceback() adds one more entry? Duncan

Arguably, R was not designed or evolved for truly novice users, nor really was Python or just about all computer languages. As they evolved and became in many ways more powerful, they tended to get ever less user friendly in the way you are asking for and gotten so bloated that many features are not familiar even to expert users. Compiled languages can have ways to keep track of what LINE of code

And now I've found the elusive bug in show.error.locations = TRUE as well, and posted a patch for that too. Back to the original topic of this thread: I think most users should routinely use options(show.error.locations = TRUE) e.g. in their .Rprofile. That will often speed up bug fixes, especially if my patch is incorporated. Duncan Murdoch On 2025-01-20 5:56 p.m., Duncan Murdoch

On 2025-01-18 8:27 p.m., Ivo Welch wrote: > I am afraid my errors are worse! (so are my postings. I should have > given an example.) > > ``` > x <- 1 > y <- 2 > nofunction("something stupid I am doing!") > z <- 4 > ``` > > and > > ``` >> source("where-is-my-water.R") > Error in nofunction("something stupid I am

I am afraid my errors are worse! (so are my postings. I should have given an example.) ``` x <- 1 y <- 2 nofunction("something stupid I am doing!") z <- 4 ``` and ``` > source("where-is-my-water.R") Error in nofunction("something stupid I am doing!") : could not find function "nofunction" ``` and no traceback is available.

in a long program, I ran into ?*** caught segfault *** address 0xdc3f9b48, cause 'memory not mapped' Traceback: ?1: rep.int(seq_len(nx), rep.int(rep.fac, nx)) ?2: rep.int(rep.int(seq_len(nx), rep.int(rep.fac, nx)), orep) ?3: expand.grid(seq_len(nx), seq_len(ny)) ?4: merge.data.frame(d, ss) ?5: merge(d, ss) ?6: valid.range(opt) ?7: eval.with.vis(expr, envir, enclos) ?8: eval.with.vis(ei,

dear r experts---Is there a multicore equivalent of by(), just like mclapply() is the multicore equivalent of lapply()? if not, is there a fast way to convert a data.table into a list based on a column that lapply and mclapply can consume? advice appreciated...as always. regards, /iaw ---- Ivo Welch (ivo.welch at gmail.com)

Dear R wizards: is there a clean way to assign to elements in a list? what I would like to do, in pseudo R+perl notation is f <- function(a,b) list(a+b,a-b) (c,d) <- f(1,2) and have c be assigned 1+2 and d be assigned 1-2. right now, I use the clunky x <- f(1,2) c <- x[[1]] d <- x[[2]] rm(x) which seems awful. is there a nicer syntax? regards, /iaw ---- Ivo Welch

every time I read the R release notes for the next release, I see many functions that I had forgotten about and many functions that I never knew existed to begin with. (who knew there were bibtex facilities in R? obviously, everyone except me.) I wonder whether there is a complete list of all R commands (incl the standard packages) somewhere, preferably each with its one-liner AND

is it possible to throw a stop() that is so hard that it will escape even tryCatch? /iaw ---- Ivo Welch (ivo.welch at gmail.com)

dear R experts---I am using the coef() function to pick off the coefficients from an lm() object. alas, I also need the standard errors and I need them fast. I know I can do a "summary()" on the object and pick them off this way, but this computes other stuff I do not need. Or, I can compute (X' X)^(-1) s^2 myself. Has someone written a fast se() function? incidentally, I think

dear R experts--- I am experimenting with multicore processing, so far with pretty disappointing results. Here is my simple example: A <- 100000 randvalues <- abs(rnorm(A)) minfn <- function( x, i ) { log(abs(x))+x^3+i/A+randvalues[i] } ?## an arbitrary function ARGV <- commandArgs(trailingOnly=TRUE) if (ARGV[1] == "do-onecore") { ?library(foreach) ?discard <-