similar to: tapply not simplifying to vector? (PR#320)

The code below illustrates some points about results from tapply that I find strange. I wonder if they are intended and if so why it is so. 1) When you make a table the dimnames is a *named* list, tapply returns an unnamed list. 2) data.frame behaves differently on an array and a table. Is this an intended feature? 3) For tables class(TAB) and attr(TAB,"class") both return

Hello, I have a vector containing strings of simple operation methods. methods <- c("mean","sd","median") e.g. Now, I'd like to apply these methods to my data and I thought, I could make a do.call. But these methods don't need any further arguments... Do I have to create an empty argument list? I wanted to use a tapply( data, factor, ??? do.call

Hi all, We are facing a problem while introducing ourselves to Reshape package use. Melt seems to work fine, but cast fails when we use mean as fun.aggregate. As you see here, length and sum work fine, but mean throws this same error whatever dataset we use. > cast(aqm, month ~ variable, length) month ozone solar.r wind temp 1 5 26 27 31 31 2 6 9 30 30

Though tapply(x, factor, fun, simplify =TRUE) should be equivalent to sapply(split(x, factor), fun, simplify=TRUE), note simplify=TRUE, it is not so if fun() returns a vector rather than a scalar, e.g. > tapply(1:6, c(0,0,0,1,1,1), function(x) c(min=min(x), max=max(x)), simplify=TRUE) $"0" min max 1 3 $"1" min max 4 6 > sapply(split(1:6, c(0,0,0,1,1,1)),

Dear R-developers, when tapply() is invoked on factors that have empty levels, it returns NA. This behaviour is in accord with the tapply documentation, and is reasonable in many cases. However, when FUN is sum, it would also seem reasonable to return 0 instead of NA, because "the sum of an empty set is zero, by definition." I'd like to raise a discussion of the possibility of an

> On Jan 26, 2017 07:50, "William Dunlap via R-devel" <r-devel at r-project.org> > wrote: > It would be cool if the default for tapply's init.value could be > FUN(X[0]), so it would be 0 for FUN=sum or FUN=length, TRUE for > FUN=all, -Inf for FUN=max, etc. But that would take time and would > break code for which FUN did not work on

On Fri, Jan 27, 2017 at 12:34 AM, Martin Maechler <maechler at stat.math.ethz.ch> wrote: > > > On Jan 26, 2017 07:50, "William Dunlap via R-devel" <r-devel at r-project.org> > > wrote: > > > It would be cool if the default for tapply's init.value could be > > FUN(X[0]), so it would be 0 for FUN=sum or FUN=length, TRUE for >

It would be cool if the default for tapply's init.value could be FUN(X[0]), so it would be 0 for FUN=sum or FUN=length, TRUE for FUN=all, -Inf for FUN=max, etc. But that would take time and would break code for which FUN did not work on length-0 objects. Bill Dunlap TIBCO Software wdunlap tibco.com On Thu, Jan 26, 2017 at 2:42 AM, Martin Maechler <maechler at stat.math.ethz.ch> wrote:

The "no factor combination" case is distinguishable by 'tapply' with simplify=FALSE. > D2 <- data.frame(n = gl(3,4), L = gl(6,2, labels=LETTERS[1:6]), N=3) > D2 <- D2[-c(1,5), ] > DN <- D2; DN[1,"N"] <- NA > with(DN, tapply(N, list(n,L), FUN=sum, simplify=FALSE)) A B C D E F 1 NA 6 NULL NULL NULL NULL 2 NULL NULL 3 6

On a related note, the storage mode should try to match ans[[1]] (or unlist:ed and) when allocating 'ansmat' to avoid coercion and hence a full copy. Henrik On Jan 26, 2017 07:50, "William Dunlap via R-devel" <r-devel at r-project.org> wrote: It would be cool if the default for tapply's init.value could be FUN(X[0]), so it would be 0 for FUN=sum or FUN=length, TRUE

Last week, we've talked here about "xtabs(), factors and NAs", -> https://stat.ethz.ch/pipermail/r-devel/2017-January/073621.html In the mean time, I've spent several hours on the issue and also committed changes to R-devel "in two iterations". In the case there is a *Left* hand side part to xtabs() formula, see the help page example using 'esoph', it

Full_Name: Hilmar Berger Version: 2.4.1/2.6.2alpha OS: WinXP Submission from: (NULL) (84.185.128.110) Hi all, If I use tapply on an empty data.frame I get an error. I'm not quite sure if one can actually expect the function to return with a result. However, the error message suggests that this case does not get handled well. This happens both in R-2.4.1 and 2.6.2alpha (version 2008-01-26).

Hello, I found rather surprising the behaviour of POSIXct and POSIXlt classes when combined with min and tapply. The details can be deduced from the script below: ############# Start of the script #################### before <- Sys.time() Sys.sleep( 1 ) now1 <- now2 <- Sys.time() my.times <- c( before, now1, now2 ) class( my.times ) ## [1] "POSIXct"

Hello everyone, I want to calculate type I error rate for modified F statistic for one way robust anova. I need to find the j group trimmed mean and winsorized sum of squared deviations. Here I attached my code for j=2 to make it simple. Originally I have j=4. Hope you can help. I need to run it for 1000 times My problem is: i) the value of F-test obtain from my simulation below is in negative

Function 'aggregate.data.frame' in R has taken a different route. With drop=FALSE, the function is also applied to subset corresponding to combination of grouping variables that doesn't appear in the data (example 2 in https://stat.ethz.ch/pipermail/r-devel/2017-January/073678.html). Because 'default' is used only when simplification happens, putting 'default' after

summary: The function 'by' inconsistently strips class from the data to which it is applied. quick reason: tapply strips class when simplify is set to TRUE (the default) due to the class stripping behaviour of unlist. quick answer: This can be fixed by invoking tapply with simplify=FALSE, or changing tapply to use do.call(c instead of unlist executable example:

The function tapply is not working in the Windows version of R=20 (Version 0.50 Beta (Sept 29, 1997)) In tapply <- function (x, INDEX, FUN=3DNULL, simplify=3DTRUE, ...)=20 ... The part: if (simplify && all(unlist(lapply(ans, length)) =3D=3D 1)) { ans <- unlist(ans, recursive =3D FALSE) names(ans)<-namelist[[1]] return(ans) } should be replaced by if (simplify

Hi, This is Kotien Wu from NIH/NCI. We want to use R function for our web: http://cgap.nci.nih.gov It works for functions in R/R-1.9.1/src/nmath/standalone very well. We have function GetPvalueForT.c which has #define MATHLIB_STANDALONE 1 #include <Rmath.h> double GetPvalueForT ( double t, double deg ) { return 2 * pt(t, deg, 0, 0); } We create GetPvalueForT.i, which has /* File :

Hi! I'm trying to do a lm() test on three objects. My problem is that R protests and says that the variable lengths differ for one of the objects (Sweden.GDP.gap). But I have double checked that the number of observations are the same. All three objects should contain 9 observations but R only accepts 9 observations in two of the objects. The third must have 10! Very confusing because there

Does anyone else miss email-friendly character graphics such as the following example, produced using Minitab? Histogram of C6 N = 478 N* = 21 Each * represents 2 observation(s) Midpoint Count -12 16 ******** -11 53 *************************** -10 63 ******************************** -9 83