similar to: Small change to "cut.default"

Hi everyone, I do a lot of work with large variance matrices, and I like to use "crossprod" for speed and to keep everything symmetric, i.e. I often compute "crossprod(Q %*% t(A))" for "A %*% Sigma %*% t(A)", where "Sigma" decomposes as "t(Q) %*% Q". I notice in the code that "crossprod", current definition > crossprod function (x,

Hi everyone, Can I suggest an addition to the help page for logical AND and OR, indicating the behaviour of NA (which is currently not mentioned at all). I think something simple like an extra paragraph in Details, eg \code{NA} is a valid logical object. Where a component of \code{x} or \code{y} is \code{NA}, the result will be \code{NA} if the outcome is ambiguous. In other words \code{NA

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

Filed as a bug, as suggested by Brian R., Jonathan. Jonathan Rougier Science Laboratories Department of Mathematical Sciences South Road University of Durham Durham DH1 3LE tel: +44 (0)191 374 2361, fax: +44 (0)191 374 7388 http://www.maths.dur.ac.uk/stats/people/jcr/jcr.html ---------- Forwarded message ---------- Date: Wed, 11 Apr 2001 09:15:26 +0100

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)

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 +

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

Hi Everyone, To complete the outer() and kronecker() functions in the base, may I suggest the following tensor() function, which allows the multiplication of arrays through sets of conformable dimensions. I am happy to write a help page if required. The code also needs a setdiff() function which prompts me to ask: what about simple set functions? I expect many of us have written our own

In legend() is it possibly to mix lines and boxes? I would like to do something like legend(locator(1), legend = c("al", "ben", "chris", "dave"), lty = c(1, 2, 3, NA), fill = c(NA, NA, NA, "gray")) to indicate that "al", "ben" and "chris" have lines, and "dave" has a gray shading. Many thanks,

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

Hi Everyone, I have modified my version of R-1.4.1 to include choleski with pivoting (like in Splus). I thought R-core might consider including this in the next version of R, so I give below the steps required to facilitate this. 1. Copied Linpack routine "dchdc.f" into src/appl 2. Inserted line F77_SUBROUTINE(dchdc) in src/appl/ROUTINES 3. Inserted "dchdc.f" into

Can I suggest that in cov and cor the lines if (is.data.frame(x)) x <- as.matrix(x) if (is.data.frame(y)) y <- as.matrix(y) be replaced by if (is.data.frame(x)) x <- data.matrix(x) # coerce logical and factors if (is.data.frame(y)) y <- data.matrix(y) # likewise This would allow things like > data(iris) > cor(iris) which

The following gives an immediate segmentation fault, v 0.90.1 "fred" <- function(x) { print(x); Recall(x-1)} fred(0) # segmentation fault at recursion 831 Obviously this recursion is non-terminating, but shouldn't it be caught and reported at some limit? In 0.64.1 we had Error: protect(): stack overflow at recursion 831. Cheers, Jonathan. Jonathan Rougier

Hi Everyone, I have a piece of C code that uses R_alloc, and so I set DUP=TRUE in the call using ".C". As I understand it this takes a copy of each object passed to my function. If these objects are large then this could be expensive. My question is, if I rewrote the code to use .Call, would I avoid this duplication by using the objects themselves (they are not modified in the code)

Hi everyone, Can I suggest an additional output component in cancor, from package mva? It would be useful to have the number of canonical correlation vectors, equivalently the rank of the covariance between x and y (label "rank"). This would usually be min(dx, dy), where dx and dy have already been computed for the svd function, but there might be situations where it was less than

According to the assign helpfile (0.90.1) the "assign" function is function (x, value, pos = -1, envir = sys.frame(sys.parent()), inherits = FALSE, immediate = TRUE) which is not quite the implementation, which is function (x, value, pos = -1, envir = pos.to.env(pos), inherits = FALSE, immediate = TRUE) This seems to have the following interesting effect. "short.fun"

Hi everyone, As "intensities" is deprecated as a synonym for "density" in the output of hist it would be a good idea to replace its occurence with "density" in plot.histogram, where we currently have y <- if (freq) x$counts else x$intensities Note that, to add to the confusion, x$density is also referred to in plot.histogram. Cheers, Jonathan.

Hi Everyone, We have just upgraded to R-1.2.1, and I note, in contrast to R-1.1.1, that ctest is now loaded automatically. The mechanism for this is to create a .First function in base: .First <- function() { require("ctest", quietly=TRUE) } Now I don't want ctest, but I find that simply putting if (length(grep("ctest", search()))) detach(package:ctest) into

Hi everyone, Can I suggest the following modification of outer for R-1.3, in the interests of speed and size of calculation: ******************************************************************* "outer" <- function (X, Y, FUN = "*", ...) { no.nx <- is.null(nx <- dimnames(X <- as.array(X))) dX <- dim(X) no.ny <- is.null(ny <- dimnames(Y <-