Displaying 20 results from an estimated 300 matches similar to: "Handling masked methods"
2009 Mar 10
1
S4 generic masking S3 generic when using namespace
Hi,
I have two example packages, test1 and test2, where the only code in
them is:
setGeneric("predict", function(object, ...) standardGeneric("predict"))
(get them from http://www.cs.mu.oz.au/~gabraham/test1.tar and
http://www.cs.mu.oz.au/~gabraham/test2.tar)
The difference between them is that first does not have a namespace, and
loads fine. The second has a namespace
2008 Apr 03
1
Lapack error in Design:::ols
Hi,
I'm trying to use Frank Harrell's Design:::ols function to do regression
of y (numeric) on the interaction of two factors (x1 and x2), but Lapack
throws an error:
> library(Design)
...
> load(url("http://www.csse.unimelb.edu.au/~gabraham/x"))
> ols(y ~ x1 * x2, data=x)
Error in chol2inv(fit$qr$qr) : 'size' cannot exceed nrow(x) = 20
> traceback()
2008 Oct 18
0
Error in solvet: apparently singular matrix
Hi,
Again I'm doing logistic regression using lrm from Harrell's Design
package, but on wide matrices (28 observations, 1891 variables) so L2
penalisation is used. I get the following error, although I've tried
different penalties and different tolerances. The X matrix is scaled and
centred.
> library(Design)
>
2009 Jun 24
1
Rscript segfaults with lazy loading
Hi,
I have an RData file containing a GeneSetCollection object
(Bioconductor), http://www.cs.mu.oz.au/~gabraham/c2.RData. I think it
uses lazy loading because packages are only loaded when I access the
object (see below) in the R console.
When I try the same with Rscript, it segfaults. This happens on 2.9.0
both on Linux and Mac:
Rscript -e 'load("c2.RData"); c2[1]'
***
2008 May 18
1
predict.prcomp: 'newdata' does not have the correct number of columns
Hi,
I'm doing PCA on wide matrices and I don't understand why calling
predict.prcomp on it throws an error:
> x1 <- matrix(rnorm(100), 5, 20)
> x2 <- matrix(rnorm(100), 5, 20)
> p <- prcomp(x1)
> predict(p, x2)
Error in predict.prcomp(p, x2) :
'newdata' does not have the correct number of columns
> dim(x2)
[1] 5 20
> dim(p$rotation)
[1] 20 5
2008 May 16
1
Dimensions of svd V matrix
Hi,
I'm trying to do PCA on a n by p wide matrix (n < p), and I'd like to
get more principal components than there are rows. However, svd() only
returns a V matrix of with n columns (instead of p) unless the argument
nv=p is set (prcomp calls svd without setting it). Moreover, the
eigenvalues returned are always min(n, p) instead of p, even if nv is set:
> x <-
2008 Aug 12
1
Conflict between octave3.0-headers and r-base-dev
Hi,
I'm using Ubuntu Hardy i386, and the R 2.7.1 Ubuntu packages from CRAN.
The CRAN r-base-dev package depends on refblas3-dev or atlas3-base-dev,
but octave3.0-headers depends on libblas-dev. The two blas packages seem
to conflict, so r-base-dev and octave3.0-headers can't be installed
together.
Is this a known issue?
Thanks,
Gad
$ sudo apt-get install octave3.0-headers
Reading
2010 May 26
2
cran2deb Packages.bz2 Hash Sum mismatch
Hi,
I'm using Ubuntu 9.10 amd64 with cran2deb packages (I know it's meant
for Debian, it's worked fine for me for many months).
Recently apt-get update has to started to complain:
...
Hit http://debian.cran.r-project.org testing/ Release
Get:1 http://debian.cran.r-project.org testing/ Packages [515kB]
Fetched 1B in 3s (0B/s)
W: Failed to fetch
2009 Nov 27
2
Symmetric Matrix classes
Hi,
I'd like to store large covariance matrices using Matrix classes.
dsyMatrix seems like the right one, but I want to specify just the
upper/lower triangle and diagonal and not have to instantiate a huge
n^2 vector just for the sake of having half of it ignored:
Dumb example:
M <- new("dsyMatrix", uplo="U", x=rnorm(1e4), Dim=as.integer(c(100, 100)))
diag(M) <- 1
2008 Apr 20
1
Scaling in predict.prcomp
Hi,
Say x.train is a matrix of covariates that I want to do PCA on, so I can
do regression on its principal components, and x.test is a test set of
the same covariates on which I want to evaluate the regression fit. I
would like the covariates to be centred and scaled:
p <- prcomp(x.train, center=TRUE, scale=TRUE)
x.train.pc <- predict(p)
Now I want to get the PCs from the test set.
2008 Apr 17
1
Error in Design package: dataset not found for options(datadist)
Hi,
Design isn't strictly an R base package, but maybe someone can explain
the following.
When lrm is called within a function, it can't find the dataset dd:
> library(Design)
> age <- rnorm(30, 50, 10)
> cholesterol <- rnorm(30, 200, 25)
> ch <- cut2(cholesterol, g=5, levels.mean=TRUE)
> fit <- function(ch, age)
+ {
+ d <- data.frame(ch, age)
+
2006 Jun 23
2
Time series labeling with Zoo
Hi,
I'm using zoo because it can automatically label the months of a time
series composed of daily observations.
This works well for certain time series lengths, but not for others, e.g.:
While:
> library(zoo)
> plot(zoo(runif(10), as.Date("2005-06-01") + 0:50))
Shows up the months and day of month,
> plot(zoo(runif(10), as.Date("2005-06-01") + 0:380))
2007 Mar 16
3
ARIMA standard error
Hi,
Can anyone explain how the standard error in arima() is calculated?
Also, how can I extract it from the Arima object? I don't see it in there.
> x <- rnorm(1000)
> a <- arima(x, order = c(4, 0, 0))
> a
Call:
arima(x = x, order = c(4, 0, 0))
Coefficients:
ar1 ar2 ar3 ar4 intercept
-0.0451 0.0448 0.0139 -0.0688 0.0010
s.e.
2006 Jun 13
3
Multiple lag.plots per page
Hi,
I'm trying to plot several lag.plots on a page, however the second plot
replaces the first one (although it only takes up the upper half as it
should):
par(mfrow=c(2,1))
a<-sin(1:100)
b<-cos(1:100)
lag.plot(a)
lag.plot(b)
What's the trick to this?
I'm using R 2.2.1 (2005-12-20 r36812) on Ubuntu Linux.
Thanks,
Gad
--
Gad Abraham
Department of Mathematics and
2007 Oct 16
2
survreg's algorithm
Hi,
I'm using survreg() from the survival package for parametric survival
regression (modelling inter-arrival times of patients to a waiting list
as exponentially distributed, with various regressors such as queue size
and season).
Does anyone know which algorithm survreg() uses for this?
Thanks,
Gad
--
Gad Abraham
Department of Mathematics and Statistics
The University of Melbourne
2007 Dec 07
1
Make natural splines constant outside boundary
Hi,
I'm using natural cubic splines from splines::ns() in survival
regression (regressing inter-arrival times of patients to a queue on
queue size). The queue size fluctuates between 3600 and 3900.
I would like to be able to run predict.survreg() for sizes <3600 and
>3900 by assuming that the rate for <3600 is the same as for 3600 and
that for >4000 it's the same as for
2007 Mar 20
1
truehist bug?
Hi,
Is this a bug in truehist()?
> library(MASS)
> x <- rep(1, 10)
> truehist(x)
Error in pretty(data, nbins) : invalid 'n' value
Thanks,
Gad
> R.version
platform i486-pc-linux-gnu
arch i486
os linux-gnu
system i486, linux-gnu
status
major 2
minor 4.1
year 2006
month 12
day 18
svn
2007 Mar 20
1
truehist bug?
Hi,
Is this a bug in truehist()?
> library(MASS)
> x <- rep(1, 10)
> truehist(x)
Error in pretty(data, nbins) : invalid 'n' value
Thanks,
Gad
> R.version
platform i486-pc-linux-gnu
arch i486
os linux-gnu
system i486, linux-gnu
status
major 2
minor 4.1
year 2006
month 12
day 18
svn
2007 Apr 27
1
Not showing dvi with Hmisc latex()
Hi,
I'm using latex() from Frank Harrell's Hmisc library to produce LaTeX
files. By default, it calls xdvi and displays the dvi.
How can I make xdvi not show? I couldn't find a clue in the extensive
documentation.
Thanks,
Gad
ps: Hmisc 3.3-1 on R 2.5.0 for Linux.
--
Gad Abraham
Department of Mathematics and Statistics
The University of Melbourne
Parkville 3010, Victoria,
2007 May 25
0
Off topic: S.E. for cross validation
Hi,
I'm performing (blocked) 10-fold cross-validation of a several time
series forecasting methods, measuring their mean squared error (MSE).
I know that the MSE_cv is the average over the 10 MSEs. Is there a way
to calculate the standard error as well?
The usual SD/sqrt(n) formula probably doesn't apply here as the 10
observations aren't independent.
Thanks,
Gad
--
Gad