Displaying 20 results from an estimated 10000 matches similar to: "Multiple lag.plots per page"
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 <-
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 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 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
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 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 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
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
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
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
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 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
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]'
***
2009 Jul 16
1
Handling masked methods
Hi,
Say I have two packages, test1 and test2, that both define the generic
method train (identical definition), and each has a specific train
method for a different S4 object (foo and bar, resp.)
I want to be able to call train(foo, x, y) and train(bar, x, y), which
doesn't work since test2 masks test1, as seen below.
The two solutions I can think of are to a) prefix train,
2007 Mar 15
1
expm() within the Matrix package
Hi
Could anybody give me a bit of advice on some code I'm having trouble with?
I've been trying to calculate the loglikelihood of a function iterated over
a data of time values and I seem to be experiencing difficulty when I use
the function expm(). Here's an example of what I am trying to do
y<-c(5,10) #vector of 2 survival times
p<-Matrix(c(1,0),1,2) #1x2 matrix
2008 Feb 21
1
bootstrap: definition of original statistic
Hi,
In the boot package, the original statistic is simply the statistic
function evaluated on the original data (called t0).
However, in Harrell et al 1996 "Multivariable prognostic models..."
Stats Med vol 15, pp. 361--387, it is different (p. 372):
The statistic function evaluated on the original data is called
"D_app" (apparent statistic), whereas "D_orig"
2009 Apr 09
1
arima on defined lags
Dear all,
The standard call to ARIMA in the base package such as
arima(y,c(5,0,0),include.mean=FALSE)
gives a full 5th order lag polynomial model with for example coeffs
Coefficients:
ar1 ar2 ar3 ar4 ar5
0.4715 0.067 -0.1772 0.0256 -0.2550
s.e. 0.1421 0.158 0.1569 0.1602 0.1469
Is it possible (I doubt it but am
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)
+
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,