Displaying 20 results from an estimated 7000 matches similar to: "NA and help page for "&" and "|""
2002 Mar 15
1
Thought on crossprod
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,
2001 Nov 13
1
Small change to "cut.default"
Hi everyone,
Can I suggest the following cosmetic change to cut.default (R-1.3.1), to
adjust the labels in the case that include.lowest = TRUE:
arrow:dma0jcr% diff -u cut.R my.cut.R
--- cut.R Tue Nov 13 12:28:35 2001
+++ my.cut.R Tue Nov 13 12:35:16 2001
@@ -25,6 +25,11 @@
ch.br[-nb], ",", ch.br[-1],
if(right)"]"
2001 Apr 11
0
replicating lists (fwd) (PR#907)
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
2000 Mar 01
1
"is.qr" definition (PR#465)
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
2002 Feb 20
1
Pivoting in chol
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
2002 Nov 22
4
Small change to plot.xy
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)
2002 Oct 08
3
hash argument of new.env()
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
2001 Apr 11
5
replicating lists
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
2002 May 16
0
Re: [R] NaN/NA and sprintf double format (PR#1561)
ripley@stats.ox.ac.uk wrote:
>
> On Tue, 14 May 2002, Dirk Eddelbuettel wrote:
>
> > With a (late prerelease of) 1.5.0 on Windows, using sprintf on NaN
> > yields garbage when the number of decimal is specified while it
> > works fine for NA:
> >
> > > sprintf("%.2f", NA)
> > [1] "0.00"
>
> I get that on Linux too, but
1999 Aug 18
2
diag()
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 +
2001 Jun 11
1
Additional output in cancor
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
2001 Mar 29
1
Detaching "ctest"
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
2001 Mar 21
0
Suggest new outer for R-1.3
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 <-
2002 Oct 22
0
methods function
Hi everyone,
I've noticed that the methods function is incomplete. The obvious
example is if I write a function "$.foo", it is not picked up by
methods:
> "$.foo" <- function(object, name) get(name, envir=object[[1]])
> "$<-.foo" <- function(object, name, value) {assign(name, value, envir=object[[1]]); object}
> happy <-
1999 Aug 25
2
Error in ?text (PR#256)
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
2000 Nov 10
1
Modification to cov and cor
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
1999 Jul 20
2
tensor() function and sets
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
1999 Apr 30
1
legend()
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,
2000 Feb 01
2
Segmentation fault in recursion, 0.90.1 (PR#409)
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
2000 Sep 07
1
.C and DUP=TRUE versus .Call
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)