similar to: Using the ``...'' argument.

I have factors with levels ``Unit", "Achieved", and "Scholarship"; I wish to replace these with "U", "A", and "S". So I do fff <- factor(fff,labels=c("U","A","S")) This works as long as all of the levels are actually present in the factor. But if ``Scholarship'' is absent (as if often is) then

Is there a way of calculating the derivative of a function returned by splinefun()? Such a function is a cubic spline, whence it has a calculable derivative, but is there a (simple) way of getting at it? One workaround that I have thought of is to take a fine grid of points, evaluate the function returned by splinefun() at these points, put an interpolating spline through these points using

A colleague asked me if there is a way to specify with a ***variable*** (say ``cflag'') whether there is an intercept in a linear model. She had in mind something like lm(y ~ x - cflag) where cflag could be 0 or 1; if it's 0 an intercept should be fitted, if it's 1 then no intercept. This doesn't work ``of course''. The cflag just gets treated as another predictor

Dimitris Rizopoulos wrote: > look at ?rowMeans; you can also use "apply(mat, 1, mean)" but > rowMeans() is better. By my reading of the question, this is not what Ezhil wants. He said: ``I have a 992 x 74 matrix. I would like to form a new matrix by averaging each 4 rows from the original one.'' I.e. he wants (I think) the first row of the new matrix to be the

Just now I again had occasion to want nested describe lists in a documentation file. I found that the bug which I reported on 18 October, 2001 still persists. I checked on the bug report at the R web page, and found that the notes say ``Not a problem in R 1.4.0 (2001-12-08)''. Well, it's still a problem for me --- using R 1.4.1. (Details: platform sparc-sun-solaris2.7 arch

I'm experiencing a new and annoying phenomenon which seems to consist of an unfortunate interaction between R-1.7.0 and netscape version 7. When I invoke help.start(), a netscape window duly appears with the browser pointed at the file .../R/doc/html/index.html as one would hope and expect. However if I then ask for help on a function, e.g. > help(glm) the help does NOT get displayed

I have a really simple question I have a data frame of 8 variables (the first column is the subjects' id): SubID G1 G2 G3 G4 W1 W2 W3 W4 1 6 5 6 2 6 2 2 4 2 6 4 7 2 6 6 2 3 3 5 5 5 5 5 5 4 5

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

I wish to pass a vector ``y'', some of whose entries are NAs to a fortran subroutine which I am dynamically loading and calling by means of .Fortran(). The subroutine runs through the vector entry by entry; obviously I want to have it do one thing if y[i] is present and a different thing if it is missing. The way I am thinking of proceeding is along the xlines of: ymiss <- is.na(y)

I would like to centre titles for pairs of plots in a 3-x-2 array. Each row of the array corresponds to a calendar year and I would like to have the year value centred between the two plots in the row, and just above their upper edges. I have attached an example in "demo.pdf" showing roughly what I want. I managed to produce the example using

I have just installed R version 2.14.0 and tried to re-build and re-check some of the packages that I maintain. I'm getting a warning (in the process of running R CMD check on my "deldir" package): > * checking PDF version of manual ... WARNING > LaTeX errors when creating PDF version. > This typically indicates Rd problems. > LaTeX errors found: > ! Font

I don't know from the nortest package, but it should ***always*** be the case that you test hypotheses H_0: The data have a normal distribution. vs. H_a: The data do not have a normal distribution. So if you get a p-value < 0.05 you can say that ***there is evidence*** (at the 0.05 significance level) that the data are not from a normal distribution. If the nortest package does

In checking over the solutions to some homework that I had assigned I observed the fact that in R (version 2.4.0) pnorm(-1.46) gives 0.07214504. The tables in the text book that I am using for the course give the probability as 0.0722. Fascinated, I scanned through 5 or 6 other text books (amongst the dozens of freebies from publishers that lurk on my shelf) and found that some agree with R

Suppose I have a data frame with two columns ``district'' and ``score'' --- score is numeric; district may be considered categorical. I wish to append to this data frame a third column whose entries are the ranks of ``score'' ***within*** district. I've tried fiddling about with tapply() and by() but the result is a list whose i-th component consists of the ranks of

I just tried to install R version 1.5.1, and it is failing ``make check'', as follows: $ make check `Makedeps' is up to date. running code in 'base-Ex.R' ...*** Error code 1 make: Fatal error: Command failed for target `base-Ex.Rout' Current working directory /home1/faculty/rolf/Traal/Rtmp/R-1.5.1/tests/Examples *** Error code 1 make: Fatal error: Command failed for target

I mis-spoke. It seems I had two collections of functions in the same directory. One by Colin Goodall, and one by David Scott (I have no record of where he is/was located). It is the *latter* collection that does all its work from within Fortran. I'll have another look at what Colin Goodall actually wrote to see if it could be useful to guarav. cheers, Rolf Turner rolf at

I have just been bitten by a quirk in the behaviour of model.matrix. I used model.matrix inside a function, and passed to it a formula that was built elsewhere. The formula was of the form ``y ~ x + w + z''. Now, model.matrix cheerfully accepts formulae of this form, although it only ***needs*** the right hand side, i.e. ``~ x + w + z'' --- the ``y'' can be dropped (but

Our computing services people have recently reconfigured the Sun compilers structure on our network, and I can no longer install, on our Sun/Solaris machine, a certain package (spatstat) with which I am heavily involved. (The same problem may well pertain to other packages as well; I haven't yet experimented except with spatstat.) Strictly speaking I can ***install*** it, but when I try to

I've just installed version 1.4.0 of R, and am experiencing a puzzling phenomenon with the library() function. I have .lib.loc set as follows: > .lib.loc [1] "/usr/local/lib/R/library" "/home/faculty/rolf/Rlib" If I invoke > library(melvin) I get the error message Error in library(melvin) : There is no package called `melvin' but if I invoke >

Apologies for the off-topic question; as usual I'm trying to draw upon the unparalleled knowledge and sagacity of the r-help list. Please reply off-list if you can help me out. A collaborator of mine found a formula we need, on sheets which he had photocopied out of a book, some years ago. He cannot remember which book (he's getting to be as senile and forgetful as I am, poor bloke!).