similar to: Puzzled about a new method for "[".

On 5/11/19 3:41 AM, Hadley Wickham wrote: > For what it's worth, I don't think this strategy can work in general, > because a class might have attributes that depend on its data/contents > (e.g. https://vctrs.r-lib.org/articles/s3-vector.html#cached-sum). I > don't think these are particularly common in practice, but it's > dangerous to assume that you can restore a

On 4/11/19 10:31 AM, Duncan Murdoch wrote: > On 03/11/2019 4:11 p.m., Rolf Turner wrote: >> >> I recently tried to write a new method for "[", to be applied to data >> frames, so that the object returned would retain (all) attributes of the >> columns, including attributes that my code had created. >> >> I thrashed around for quite a while, and

For what it's worth, I don't think this strategy can work in general, because a class might have attributes that depend on its data/contents (e.g. https://vctrs.r-lib.org/articles/s3-vector.html#cached-sum). I don't think these are particularly common in practice, but it's dangerous to assume that you can restore a class simply by restoring its attributes after subsetting. Hadley

On 03/11/2019 6:43 p.m., Rolf Turner wrote: > > On 4/11/19 10:31 AM, Duncan Murdoch wrote: > >> On 03/11/2019 4:11 p.m., Rolf Turner wrote: >>> >>> I recently tried to write a new method for "[", to be applied to data >>> frames, so that the object returned would retain (all) attributes of the >>> columns, including attributes that my

On 04/11/2019 4:40 p.m., Pages, Herve wrote: > Hi Rolf, > > On 11/4/19 12:28, Rolf Turner wrote: >> >> On 5/11/19 3:41 AM, Hadley Wickham wrote: >> >>> For what it's worth, I don't think this strategy can work in general, >>> because a class might have attributes that depend on its data/contents >>> (e.g. >>>

On 03/11/2019 4:11 p.m., Rolf Turner wrote: > > I recently tried to write a new method for "[", to be applied to data > frames, so that the object returned would retain (all) attributes of the > columns, including attributes that my code had created. > > I thrashed around for quite a while, and then got some help from Rui > Barradas who showed me how to do it, in

You can try for testing with a column of class errors, from the package 'errors'. The attributes depend on the content in the way Hadley pointed out. I?aki El lun., 4 nov. 2019 23:19, Rolf Turner <r.turner at auckland.ac.nz> escribi?: > On 5/11/19 10:54 AM, Duncan Murdoch wrote: > > On 04/11/2019 4:40 p.m., Pages, Herve wrote: > >> Hi Rolf, > >> >

This may be an FAQ, but a (perfunctory) search failed to turn it up. Suppose I have a function foo(...){<something>} and I want to obtain, inside foo, the names of items comprising the ``...''. E.g. if I call foo(melvin,clyde,irving) I want to be able to loop through the ``...'' and successively obtain the text strings "melvin", "clyde", and

On 5/11/19 10:54 AM, Duncan Murdoch wrote: > On 04/11/2019 4:40 p.m., Pages, Herve wrote: >> Hi Rolf, >> >> On 11/4/19 12:28, Rolf Turner wrote: >>> >>> On 5/11/19 3:41 AM, Hadley Wickham wrote: >>> >>>> For what it's worth, I don't think this strategy can work in general, >>>> because a class might have attributes

Hi all ! I noticed a strange behaviour of the function `class<-` when a class-specific '[[.' method is defined. Here below a reproducible example : #-------------------------------------------------------------------. counttt <- 0 `[[.MYCLASS` = function(x, ...) { counttt <<- counttt + 1 # browser() x = NextMethod() return(x) } df <- as.data.frame(matrix(1:20,

Hi, How to save an R object for example a matrix or vector and not all objects created in a session (which is usually performed by save.image or q("yes"))? Best, Carol [[alternative HTML version deleted]]

If one specifies new options in a package, using the options() function, where does/should one document these new options? E.g. suppose that I put the line options(melvin=42) in a file zzz.R in the R directory of the package source, where the package contains functions foo(), bar(), clyde(), and irving() which all query options("melvin") and take some action based on the value of

Dear R list members I am trying to improve a boxplot with 2 data sets. I run somethinkg like boxplot(data1 ~ month, add=F, col = "red", ...) boxplot(data2 ~ month, add=T, col = "blue", ...) The problem is that the data from February are missing for data2, so R think that must take little more space between the data classes in data 2 and then both data gropus are not aligned.

Hello, Clean R 3.6.1 session on Ubuntu 19.04, RStudio 1.1.453. sessionInfo() at the end. I can reproduce this. counttt <- 0 `[[.MYCLASS` = function(x, ...) { counttt <<- counttt + 1 # browser() x = NextMethod() return(x) } df <- as.data.frame(matrix(1:20, nrow=5)) class(df) <- c("MYCLASS","data.frame") counttt #[1] 9 But there's more. I

R CMD check tells me * checking R code for possible problems ... NOTE agexact.fit.rds: ... may be used in an incorrect context: ?optim(init, agfitfn, ...)? Warning: <anonymous>: ... may be used in an incorrect context: ?optim(init, agfitfn, ...)? Can anyone tell me what this message means? My searches haven't turned up anything useful. This is with R 2.7 and 2.9. The message

Dear forum, I would like to use the kernel2d or spkernel2d in the Splancs-package, but it does not recognize my polygon data. "Error in kernel2d(as.points(ptsbin), polygonprov, h0 = 2, nx = 100, : " is the error message. Invalid poly argument The data are defined as follows: polgonprov<-list(x=polyprov$X, y=polyprov$Y) with X and Y coordinates in the Lambert1972

I have been trying to write a "proper" print method for a package, and have almost gotten what I want. From a reading of the relevant section in R Extensions and the introduction to methods, I've stuck the whole business into a character object and used: NextMethod("print") However, instead of not printing quotes and displaying the usual representation of the string,

Hi! I have implemented class specific behaviour of "[[<-.myclass"<-function(). How it is posible to call the "[[.default" on an object of myclass? Eryk Dipl. bio-chem. Eryk Witold Wolski @ MPI-MG Dep. Vertebrate Genomics Ihnestrasse 73 14195 Berlin 'v' tel: 0049-30-84131285 / \ mail: wolski@molgen.mpg.de ---W-W----

I am trying to build a function in a context where the environment concept would appear to be useful. But I'm a bit foggy about this concept and would appreciate some pointers and advice. Basically the function I'm building, say foo(x,t), is a function of two variables). Depending on the value of t, foo will return one of the values f1(x), f2(x), ..., fk(x), where each of f1, ..., fk is

I had an error message while running a macro from Yudi Pawitan's web site: > source("ex2-13.r") Error in parse(file, n, text, prompt) : syntax error on line 2 Inspecting ex2-13.r I found that the error was generated by another source() command. Clearly R does not like nested source()s, which is fair enough when you think about it. Still it's something that you might want