search for: xtfrm

...combining multiple data frames derived from DataFrame and base::data.frame. I observed that the index column of intermediate tables was of class <AsIs> (automatically converted from character). The problem occurred mainly when using the sorted = T option in base::merge. This can be traced to xtfrm.AsIs being more than 100 times slower than the comparable function for character vectors. x = paste0("A_", 1:1e5) system.time({o <- xtfrm(x)}) #? user? system elapsed #? 0.325?? 0.005?? 0.332 x <- I(x) system.time({o <- xtfrm(x)}) # this calls xtfrm.AsIs # user? system elapse...

? Fri, 12 Jul 2024 17:35:19 +0200 Hilmar Berger via R-devel <r-devel at r-project.org> ?????: > This can be finally traced to base::rank() (called from > xtfrm.default), where I found that > > "NB: rank is not itself generic but xtfrm is, and rank(xtfrm(x), ....) > will have the desired result if there is a xtfrm method. Otherwise, > rank will make use of ==, >, is.na and extraction methods for classed > objects, possibly rather sl...

Hello everybody, it looks like the presense of some (do know know which) S4 methods for a given S4 class degrades the performance of xtfrm (used in 'order' in new R-devel) by a factor of millions. This is for classes that ARE derived from numeric directly and thus should be quite trivial to convert to numeric. Consider the following example: setClass("TimeDateBase", representation("numeric", mode=&qu...

...that creates an object that is essentially a classed version of numeric. I updated recently from 2.7.1 to 2.9.0, and merges involving my class suddenly took a huge performance hit. I've traced the problem to something near rank(). From NEWS, it seems rank() etc. changed in 2.8.0. Methods for xtfrm() are supposed to help, but I've had no success. There was some chatter about this in the archives back in Sept 08 (though apparently regarding S4), with a suggestion that it is related to `[.` methods. That has been my experience. In the toy example below, the problem disappears if `[.my` i...

...000000", "1.0.3.10000000", > "1.0.2.10000000"))) > [1] ?1.0.3.10000000? Thank you Jon for spotting this! This is an unintended consequence of https://bugs.r-project.org/show_bug.cgi?id=18697. The old behaviour of max(<numeric_version>) was to call which.max(xtfrm(x)), which first produced a permutation that sorted the entire .encode_numeric_version(x). The new behavioiur is to call which.max directly on .encode_numeric_version(x), which is faster (only O(length(x)) instead of a sort). What do the encoded version strings look like? x <- numeric_version(...

In R devel, function 'factor' has been changed, allowing and merging duplicated 'labels'. Issue 1: Handling of specified 'labels' without duplicates is slower than before. Example: x <- rep(1:26, 40000) system.time(factor(x, levels=1:26, labels=letters)) Function 'factor' is already rather slow because of conversion to character. Please don't add slowdown.

...this is not implemented. There is no claim that it works (let alone works well) for class "difftime". If you follow the link to 'sort' it says The default ?sort? method makes use of ?order? for objects with classes, which in turn makes use of the generic function ?xtfrm?. and from ?xtfrm The default method will make use of ?==? and ?>? methods for the class of ?x[i]? (for integers ?i?), and the ?is.na? method for the class of ?x?, but might be rather slow when doing so. So, if you want this to be fast, you need to write an xtfrm method. Th...

I have found that order() fails in a rather arcane circumstance, as in this example: > foo <- I( c('x','\265g') ) > order(foo) Error in if (xi > xj) 1L else -1L : missing value where TRUE/FALSE needed > foo <-c('x','\265g') > order(foo) [1] 1 2 > sessionInfo() R version 3.1.1 (2014-07-10) Platform: x86_64-apple-darwin13.1.0 (64-bit)

Full_Name: Hong Ooi Version: 2.10.0 OS: Windows XP Submission from: (NULL) (203.110.235.1) While trying to get summary statistics on a duration variable (the difference between a start and end date), I ran into the following issue. Using summary or quantile (which summary calls) on a difftime object takes an extremely long time if the object is even moderately large. A reproducible example:

I've noticed something in R devel which seems a little off and not the behavior I see in 4.4.0 or earlier versions. With numeric_versions that have long (>8 digit) final components max and min return the first element and not the max or min: In devel: > max(numeric_version(c("1.0.1.100000000", "1.0.3.100000000", "1.0.2.100000000"))) [1] ?1.0.1.100000000?

...r in factor construction. > Another thing: Function 'factor' in R devel uses 'order' instead of 'sort.list'. This has been by a change on purpose --- well documented as new feature in NEWS --- to allow using *methods* for order(), i.e. for the workhorse of order, xtfrm() so that factor(OB) works for more general objects OB. > The case of as.factor(x) for > x <- as.data.frame(character(0)) > in tests/isas-tests.Rout.save reveals that 'order' on data frame is strange. > x <- as.data.frame(character(0)) > y <-...

...r in factor construction.?? ? ? > Another thing: Function 'factor' in R devel uses 'order' instead of 'sort.list'. This has been by a change on purpose --- well documented as new feature in NEWS --- to allow using *methods* for order(), i.e. for the workhorse of order, xtfrm()? so that factor(OB) works for more general objects OB. ? ? > The case of as.factor(x) for ? ? > x <- as.data.frame(character(0)) ? ? > in tests/isas-tests.Rout.save reveals that 'order' on data frame is strange. ? ? > x <- as.data.frame(character(0)) ? ? > y <-...

Here's an example (session info at the end). > tmpv <- c('\265g/L','Bq/L') > order(tmpv) [1] 2 1 > tmpv <- I(tmpv) > order(tmpv) Error in if (xi > xj) 1L else -1L : missing value where TRUE/FALSE needed > foov <- gsub('\265','',tmpv) > order(foov) [1] 2 1 > str(tmpv) Class 'AsIs' chr [1:2] "\265g/L"

...w.names which is I(row.names(x)) to the corresponding input table (using I() since revision 39026 to avoid conversion of character to factor). When this column is used for sorting (sort=TRUE by default in merge; should happen at least if all.x=T or all.y=T), this will result in slower execution. xtfrm.AsIs is unchanged since its addition in r50992 (likely unrelated to the former). So I guess that this just went unnoticed since it will not cause problems on small data frames. Best regards Hilmar [[alternative HTML version deleted]]

Hi, I have a data frame with variables a, b, c (character vars) and t (time var, could be represented as POSIXct or character, depending on which is most useful. The format is "yyyy-mm-dd hh:mm:ss CET"). Now, I want to sort the data frame in ascending order by a, b, c and then in descending order by t. Here's what I've got, but I'm not sure how to put the

...max(pp2 <- package_version(c("1.0.3","1.0.4","1.0.5"))) ## [1] ?1.0.5? I've looked at ?package_version , to no avail. Since max() goes to .Primitive("max") I'm having trouble figuring out where it goes from there: I **think** this is related to ?xtfrm , which goes to .encode_numeric_version, which is doing something I really don't understand (it's in base/R/version.R ...) .encode_numeric_version(pp1) ## [1] 1 1 1 ## attr(,"base") ## [1] 99999912 ## attr(,"lens") ## [1] 3 3 3 ## attr(,".classes") ## [1] &quo...

...; [78] "seq.int" "sign" "signif" "sin" "sinh" "sqrt" "sum" [85] "tan" "tanh" "trigamma" "trunc" "xtfrm" "|" Which confuses me, because the calling code in tests\\primitives.R removes the first 15 elements, which includes ">=" which the test is failing on. To check (and because testInstalledBasic is calling out to a separate, new R process), I repea...

...which is I(row.names(x)) to the corresponding input table (using I() since revision 39026 to avoid conversion of character to factor). When this column is used for sorting (sort=TRUE by default in merge; should happen at least if all.x=T or all.y=T), this will result in slower execution. > > xtfrm.AsIs is unchanged since its addition in r50992 (likely unrelated to the former). > > So I guess that this just went unnoticed since it will not cause problems on small data frames. > > Best regards > > Hilmar > > [[alternative HTML version deleted]] > > ______________...

Hi, everyone, I was trying to sort a data frame by two columns, one increasing, the other decreasing and got an error. "Error in FUN(left) : invalid argument to unary operator", The command is "BA[order(BA[1],-BA[2]),]". BA is the data frame. It was working if I used increasing on both columns. Why the decreasing symbol "-" is not working here? Thanks. -- Jun

...ets[1:10, "DAX"]) daxr <- diff(log(dax)) identical(as.vector(qnorm(daxr)), qnorm(coredata(daxr))) qqnorm(coredata(daxr)) qqnorm(daxr) qqnorm() produces an error: > qqnorm(daxr) Fehler in if (xi == xj) 0L else if (xi > xj) 1L else -1L : Argument hat L?nge 0 Calls: qqnorm ... xtfrm.default -> as.vector -> rank -> switch -> .gt Ausf?hrung angehalten However, this is not witnessed by running the script through R 2.7.2 (attached are the two output files). Incidentally, the QQ-plot is produced if one uses "qqnorm(coredata(daxr))" under R version 2.8.0. Aft...