similar to: Strange behaviour of image (PR#510)

I find this a bit puzzling ... > solve(matrix(c(5, 2, 3, 1), 2, 2), c(Inf, 3)) [1] NaN Inf > solve(matrix(c(5, 2, 3, 1), 2, 2)) %*% c(Inf, 3) [,1] [1,] -Inf [2,] Inf I would expect the answer to be c(-Inf, Inf), so why has the -Inf been replaced by NaN in solve? Cheers, Jonathan. --please do not edit the information below-- Version: platform = sparc-sun-solaris2.7 arch = sparc

I was surprised to find that the variance of a scalar, using var(), is NA. Surely this should be zero? Cheers, Jonathan. --please do not edit the information below-- Version: platform = sparc-sun-solaris2.7 arch = sparc os = solaris2.7 system = sparc, solaris2.7 status = Patched major = 0 minor = 99.0 year = 2000 month = February day = 9 language = R Search Path: .GlobalEnv,

Here's a nasty one. The following has caused a segmentation fault and possibly also a bus error. fred <- 1:6 dim(fred) <- 6 dimnames(fred) <- list(LETTERS[1:6]) mm <- matrix(1:12, 2, 6) mm %*% fred # segmentation fault here In the case without the dimnames assignment the result is OK. Cheers, Jonathan. --please do not edit the information below-- Version: platform =

Might it be possible to tighten the definition of "is.qr". I noticed that after I mistakenly typed example(lm) # make lm object named lm.D9 qr.Q(lm.D9) which exhausted the heap memory and produced two warning messages. As an object of class "lm" has a "qr" component, "is.qr" failed to detect that "lm.D9" was not a "qr" object. The

I'm just back from a computer practical where we ran into > "f" <- function(x) 2(x^2) # for 2 * x^2 This definition was taken as legitimate, although using the function generated the error message > f(3) Error in f(3) : attempt to apply non-function Am I right in thinking that in prevous versions of R this definition would have been declared as a syntax error? Surely a

This situation arose in a computer practical this morning. A student overwrote "c" with a function. This messes up lots of things, but it is difficult to remove the function "c" from the global environment because it is used as a function in both "rm" and "remove". [The solution was to reassign "c" as a number, and then remove it.] Would it be

Hi everyone, Is there any reason why we should not automatically coerce a factor supplied as an argument to col in a plotting function? The following modification (to R-1.6.1) seems pretty harmless > plot.xy function (xy, type, pch = 1, lty = "solid", col = par("fg"), bg = NA, cex = 1, ...) { if (is.factor(col)) col <- codes(col)

The following seems to be odd behaviour: fred <- 1:10 mode(fred) # "numeric" exists("fred") # TRUE exists("fred", mode="numeric") # FALSE Unless I have misunderstood, the final evaluation should be TRUE, as an object called "fred" exists and its mode is "numeric". In the same category, I have just noticed that get("fred")

Hi Everyone, The following rather extreme claim on memory causes a segmentation fault on my installation: fred <- matrix(1:1200, 20, 60) littleOP <- function(x, y) { z <- as.vector(x) %*% t(as.vector(y)) dim(z) <- c(dim(x), dim(y)) z } littleOP(fred, fred) # this is OK littleOP(littleOP(fred, fred), fred) # whoops! Segmentation fault What's a bit strange

I get a segmentation fault as follows: > tmp <- array(list(), c(3, 4)) > tmp[[1, 2]] NULL # as expected > tmp[[1, 2]]$fred <- 1:10 > tmp # as expected [,1] [,2] [,3] [,4] [1,] "NULL" "List,1" "NULL" "NULL" [2,] "NULL" "NULL"

Another one from the student computer practicals: it is possible to create a dataframe that cannot be printed. Thus > fred <- data.frame(happy=c(TRUE, FALSE, TRUE), sad=7:9) > tmp <- fred[c(FALSE, FALSE, TRUE, TRUE)] # no error message! > tmp Error in as.matrix.data.frame(x) : dim<- length of dims do not match the length of object > print.default(tmp) $"NA" NULL

Hi Everyone, At the moment it is not possible to replicate complex lists, but only simple ones: > rep(list(fred = 1:10), 10) # works fine > rep(list(fred = 1:10, happy = "squash"), 10) Error in rep(list(fred = 1:10, happy = "squash"), 10) : Unimplemented feature in rep There is nothing in ?rep that suggests that the latter should not work, and I think it would

I would like to suggest a slight modification to diag(). In the case where x is a matrix with both row names and column names the same, it would be reasonable if the resulting vector also had those names. I often use diag() on variance matrices, where this modification is helpful. The modification requires replacing if (is.matrix(x) && nargs() == 1) return(c(x)[1 +

Dear all, I can not find/understand the solution to this from the help pages: Say we have the following script: x<-matrix(c(1,1,0,1,0,1,0,1,1),3,3) image(x) How can I change the ranges on the vertical and horizontal axis to a range of my own or at least place a box frame around the image if I choose to use "axes=FALSE"? Apologies for such a bsic question and thanks beforehand

Hi everyone, There is no mention in ?new.env (R-1.6.0) of what the effect of setting the hash argument of new.env() actually does. What does it mean in performance terms to say that "the environment will be hashed"? Thanks, Jonathan. -- Jonathan Rougier Science Laboratories Department of Mathematical Sciences South Road University of Durham

Jonathan Rougier <J.C.Rougier@durham.ac.uk> writes: > Would it be reasonable to suggest adding an `all' flag to save.image(), > i.e. > > "save.image" <- > function (f = ".RData", all.names = F) > eval(substitute(save(list = ls(all.names = all.names), file = f)), > .GlobalEnv) I believe this is simply a bug. I see no reason to skip the

Hi Everyone, Can I suggest a couple of new `codes' methods. I know codes is a bit dodgy (at least, according to the comments in codes.factor), but for what it's worth I like to extract codes from data frames of factors, for which the following two functions (which operate recursively) are helpful: "codes.default" <- function(x) { if (is.list(x)) lapply(x, codes)

Dear R users, Does anyone have a function for putting a legend on an image plot? I couldn't locate an R equivalent of image.legend....has anyone written such a thing? kind regards andy --------------------------------------------------------------------- J. Andy Royle, U.S. Fish and Wildlife Service - Office of Migratory Bird Management; 11510 American Holly Drive , Laurel, MD

Just a minor point, but the adj argument in ?text is described wrongly (0.64.1). Perhaps the following might be added to the details. Values of 0, 0.5, and 1 specify left/top, middle and right/bottom, respectively. The default is for centred text, ie \code{adj = c(0.5, 0.5)}. Cheers, Jonathan. Jonathan Rougier Science Laboratories Department of

Dear useRs, When plotting with image(), I would like the z-values that extend beyond the upper zlim to be indicated with one colour, or preferably with som sort of hatching, as I'm printing in black and white. By default these values just show up as blank areas in the image. I've tried all sorts of things, but nothing seems to work for me. Any solutions would be greatly appreciated.