Displaying 20 results from an estimated 4000 matches similar to: "Extract psuedo model matrix from nls?"
2002 Feb 12
1
Best Subsets regression
Hi,
I have found a minor problem with leaps(). In 1.3.1 under Windows 2000 I
seem to only be able to obtain values for one statistic at a time. That is
choosing
method=c("Cp","adjr2","r2")
just gives Cp values.
To mimic the output of Minitab's
MTB > BReg 'Fertility' 'Agriculture'-'Infant.Mortality' ;
SUBC> NVars 1 5;
SUBC>
2010 Apr 19
2
Overlay of barchart and xyplot
Hello R Folks,
I am new to R. I have been struggling to overlay a barchart with a
xyplot together on one plot but did not get this worked out. Any help
and idea are greatly appreciated.
I attached R scripts for barchart and xyplot below and also data I used.
What I am trying to do is just to put the barchart and xyplot together
on one plot.
Huapeng
<<dispersal_infestation.csv>>
2006 Jul 21
0
[Fwd: Re: Parameterization puzzle]
Bother! This cold has made me accident-prone. I meant to hit Reply-all.
Clarification below.
-------- Original Message --------
Subject: Re: [R] Parameterization puzzle
Date: Fri, 21 Jul 2006 19:10:03 +1200
From: Murray Jorgensen <maj at waikato.ac.nz>
To: Prof Brian Ripley <ripley at stats.ox.ac.uk>
References: <44C063E5.3020703 at waikato.ac.nz>
2003 Jan 12
1
likelihood and score interval estimates for glms
G'day list!
I'm thinking about programming likelihood and score intervals for
generalized linear models in R based on the paper "On the computation of
likelihood ratio and score test based confidence intervals in
generalized linear models" by Juha Alho (1992) (Statistics in Medicine,
11, 923-930).
Being lazy, I thought that I would ask if anyone else on the list has
2006 Jun 05
1
Extracting Variance components
I can ask my question using and example from Chapter 1 of Pinheiro & Bates.
> # 1.4 An Analysis of Covariance Model
>
> OrthoFem <- Orthodont[ Orthodont$Sex == "Female", ]
> fm1OrthF <-
+ lme( distance ~ age, data = OrthoFem, random = ~ 1 | Subject )
> summary( fm1OrthF )
Linear mixed-effects model fit by REML
Data: OrthoFem
AIC BIC
2008 Mar 02
2
Recommended Packages
Having just update to R 2.6.2 on my old Windows laptop I notice that the
number of packages is growing exponentially and my usual approach of
get-em-all may not be viable much longer. Has any thought been given to
dividing "contributed" binaries into a recommended set, perhaps a couple
of hundred, and the remained. That way one could install the recommended
ones routinely and add in
2006 Nov 13
2
A printing "macro"
I am exploring the result of clustering a large multivariate data set
into a number of groups, represented, say, by a factor G.
I wrote a function to see how categorical variables vary between groups:
> ddisp <- function(dvar) {
+ csqt <- chisq.test(G,dvar)
+ print(csqt$statistic)
+ print(csqt$observed)
+ print(round(csqt$expected))
+ round(csqt$residuals)
+ }
>
> x
2000 Oct 11
0
Balanced incomplete block analysis
At 07:12 AM 10-10-00 +0100, Prof Brian D Ripley wrote:
>On Tue, 10 Oct 2000, Murray Jorgensen wrote:
>
>> Excuse me everyone, but I don't have to teach this very often!
>>
>> Has anyone got some R code for doing adjusted treatment means and the
>> recovery of inter-block information in the analysis of balanced incomplete
>> block designs?
>
>Do you
2001 Sep 18
2
Error mean square
If rb.lm is an lm-object, I can access the error mean square as
s2 <- sum(rb.lm$residuals^2)/rb.lm$df.residual
This seems a bit like hard work for such a commonly wanted quantity. Is
there a better way to do this?
Murray Jorgensen
Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at
2002 Oct 28
2
Combining simulation results
In one saved workspace I have the results of a simulation experiment stored
as an array "resarray".
> dim(resarray)
[1] 10 6 500 3
In another workspace I have a similar array from another run of the
simulation.
I want to combine the two arrays into a single array of dimensions
10, 6, 1000, 3
What's the best way to do this?
Murray Jorgensen
Dr Murray Jorgensen
2010 Jun 14
2
Html help
I have just installed R 2.11.1 on my XP laptop.
I like html help for browsing but text help for on-the-fly look-ups. I
was a bit surprised when I was asked to choose between them during the
installation. I chose text, thinking I could fix the html help later,
which is what I am trying to do now.
Now when I ask for html help my browser goes to
'http://-ip-number-/doc/html/index.html'
2005 Sep 08
1
Coarsening Factors
It is not uncommon to want to coarsen a factor by grouping levels
together. I have found one way to do this in R:
> sites
[1] F A A D A A B F C F A D E E D C F A E D F C E D E F F D B C
Levels: A B C D E F
> regions <- list(I = c("A","B","C"), II = "D", III = c("E","F"))
> library(Epi)
> region <-
2009 Nov 25
2
R or C++ on FreeNX servers
Hi all,
I have just found out that the machine learning group in our Faculty has
a lot of spare capacity on their FreeNX servers. I do not know a lot
about these beasts but I understand that they are a free version of
something produced by a firm called "NoMachine".
They are designed for executing parallel algorithms and I thought that
they might be of use in a project of mine
2005 Apr 05
1
nlme & SASmixed in 2.0.1
I assigned a class the first problem in Pinheiro & Bates, which uses the
data set PBIB from the SASmixed package. I have recently downloaded
2.0.1 and its associated packages. On trying
library(SASmixed)
data(PBIB)
library(nlme)
plot(PBIB)
I get a warning message
Warning message:
replacing previous import: coef in: namespaceImportFrom(self,
asNamespace(ns))
after library(nlme) and a
2006 May 02
0
Pasting data into scan() - oops!
I forgot to mention that I am using Windows XP.
-------- Original Message --------
Subject: Pasting data into scan()
Date: Tue, 02 May 2006 11:55:03 +1200
From: Murray Jorgensen <maj at stats.waikato.ac.nz>
To: r-help at stat.math.ethz.ch
The file TENSILE.DAT from the Hand et al "Handbook of Small Data Sets"
looks like this:
[...]
--
Dr Murray Jorgensen
2000 Nov 01
0
Loop elimination question
How about:
> dim
[1] 3 1 4 1 5
> N <- length(dim)
> one <- rep(c(3,4),N)
> two <- c(rep(1,N),dim)
> three <- rep(1:N,rep(2,N))+N*rep(0:1,N)
> rep(one,two[three])
[1] 3 4 4 4 3 4 3 4 4 4 4 3 4 3 4 4 4 4 4
----------------------
Bendix Carstensen
Senior Statistician
Steno Diabetes Centre
Niels Steensens Vej 2
DK-2820 Gentofte
Denmark
tel: +45 44 43 87 38
mob: +45 28
2004 Feb 05
2
Sweave problem
Here is the file minimal.Snw:
\documentclass[a4paper]{article}
\title{R tips and tricks}
\author{Murray Jorgensen}
\usepackage{Sweave}
\begin{document}
\maketitle
\section*{Entering data from a single variable}
The following data are transformed tensile strength measurements on
polyester
fibres. They may be found on the file \texttt{TENSILE.DAT}. We
may enter this data into R using the
2003 Sep 17
5
Quit asking me if I want to save the workspace!
How do you stop R from putting up a dialog box when you quit Rgui?
(I use Windows and I never save workspaces that way)
Murray
--
Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz Fax 7 838 4155
Phone +64 7 838 4773 wk +64 7 849 6486 home
2008 Aug 24
1
Extracting formula from an lm object
I want to extra the part of the formula not including the response
variable from an lm object. For example if the lm object ABx.lm was
created by the call
ABx.lm <- lm( y ~ A + B + x, ...)
Then ACx.lm is saved as part of a workspace.
I wish to extract "~ A + B + x". Later in my code I will fit another
linear model of the form z ~ A + B + x for some other response variable z.
I
2006 Nov 13
1
stepAIC for overdispersed Poisson
I am wondering if stepAIC in the MASS library may be used for model
selection in an overdispersed Poisson situation. What I thought of doing
was to get an estimate of the overdispersion parameter phi from fitting
a model with all or most of the available predictors (we have a large
number of observations so this should not be problematical) and then use
stepAIC with scale = phi. Should this