Displaying 20 results from an estimated 3000 matches similar to: "Sweave and scan()"
2011 Jan 05
4
Converting Fortran or C++ etc to R
I'm going to try my hand at converting some Fortran programs to R. Does
anyone know of any good articles giving hints at such tasks? I will post
a selective summary of my gleanings.
Cheers, 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
2006 Apr 14
5
vector-factor operation
I found myself wanting to average a vector [vec] within each level of a
factor [Fac], returning a vector of the same length as vec. After a
while I realised that
lm1 <- lm(vec ~ Fac)
fitted(lm1)
did what I want.
But there must be another way to do this, and it would be good to be
able to apply other functions than mean() in this way.
Cheers, Murray
--
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'
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
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
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 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
2006 Aug 01
4
Fitting models in a loop
If I want to display a few polynomial regression fits I can do something
like
for (i in 1:6) {
mod <- lm(y ~ poly(x,i))
print(summary(mod))
}
Suppose that I don't want to over-write the fitted model objects,
though. How do I create a list of blank fitted model objects for later
use in a loop?
Murray Jorgensen
--
Dr Murray Jorgensen
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
2001 May 22
2
MASS data sets
I'm running R 1.2.2 under windows 98 on a Pentium 133 laptop.
I can't seem to retrieve the package MASS data sets:
> library(MASS)
> data(wtloss)
Warning message:
Data set `wtloss' not found in: data(wtloss)
> data(abbey)
Warning message:
Data set `abbey' not found in: data(abbey)
And yet all the .rda files for the MASS datasets are in
D:\Program
2006 Aug 20
3
unquoting
I would like a function to strip quotes off character strings. I should
work like this:
> A <- matrix(1:6, nrow = 2, ncol=3)
> AF <- as.data.frame(A)
> names(AF) <- c("First","Second","Third")
> AF
First Second Third
1 1 3 5
2 2 4 6
> names(AF)[2]
[1] "Second"
> attach(AF)
>
2008 Oct 11
1
step() and stepAIC()
The birth weight example from ?stepAIC in package MASS runs well as
indeed it should.
However when I change stepAIC() calls to step() calls I get warning
messages that I don't understand, although the output is similar.
Warning messages:
1: In model.response(m, "numeric") :
using type="numeric" with a factor response will be ignored
(and three more the same.)
Checked
2009 Aug 02
3
two-factor linear models with missing cells
I am wondering how to interpret the parameter estimates that lm()
reports in this sort of situation:
y = round(rnorm(n=24,mean=5,sd=2),2)
A = gl(3,2,24,labels=c("one","two","three"))
B = gl(4,6,24,labels=c("i","ii","iii","iv"))
# Make both observations for A=1, B=4 missing
y[19] = NA
y[20] = NA
data.frame(y,A,B)
nonadd = lm(y ~
2003 Dec 30
4
Assignments in loops
Greetings all. Any help with the following would be appreciated.
I want to create a data frame for each file in a directory. The following
code does not work but it may show what I am trying to do:
carmakes <- c('BMW','Chrysler','Citroen','Fiat','Ford','Holden','Honda',
2007 Dec 05
2
Dimension of a vector
Consider the following:
> A <- 1:10
> A
[1] 1 2 3 4 5 6 7 8 9 10
> dim(A)
NULL
> dim(A) <- c(2,5)
> A
[,1] [,2] [,3] [,4] [,5]
[1,] 1 3 5 7 9
[2,] 2 4 6 8 10
> dim(A)
[1] 2 5
> dim(A) <- 10
> A
[1] 1 2 3 4 5 6 7 8 9 10
> dim(A)
[1] 10
Would it not make sense to have dim(A) = length(A) for all vectors?
2007 Jan 05
4
ifelse on data frames
[Using R 2.2.0 on Windows XP; OK, OK, I will update soon!]
I have noticed some undesirable behaviour when applying
ifelse to a data frame. Here is my code:
A <- scan()
1.000000 0.000000 0.000000 0 0.00000
0.027702 0.972045 0.000253 0 0.00000
A <- matrix(A,nrow=2,ncol=5,byrow=T)
A == 0
ifelse(A==0,0,-A*log(A))
A <- as.data.frame(A)
ifelse(A==0,0,-A*log(A))
and this is the output:
2003 Aug 20
5
Interlacing two vectors
I want to interlace two vectors. This I can do:
> x <- 1:4
> z <- x+0.5
> as.vector(t(cbind(x,z)))
[1] 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
but this seems rather inelegant. Any suggestions?
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
2003 Sep 23
2
R-project [.com?] [.net?]
I got a shock a few days ago when I accidentally visited
www.r-project.com . I thought that the r-project site had been hacked
until I realised my mistake. There is also a site www.r-project.net.
Both of these sites appear to be Japanese. Does anyone know anything
about them? I suppose that it is not unusual for names close to those of
popular sites to be used. It is good that they use a
2008 Aug 26
2
lattice plotting character woes
The following reproducable code shows the setting of my problem:
set.seed(260808)
n = 50
x = rnorm(n)
y = rnorm(n)
z = ceiling(runif(n,0,4))
g = runif(n,0,6)
G = factor(ceiling(g))
xyplot(y ~ x | G)
plsy <- trellis.par.get("plot.symbol")
plsy$pch = z
trellis.par.set("plot.symbol",plsy)
xyplot(y ~ x | G)
plsy$pch = as.character(z)
2001 Oct 02
3
Accessing just the value of an object but not the attributes
I have the feeling that this is a dumb question but oh well ...
When I have an object x with several attributes,
y <- x will make a copy of x with all the attributes included.
What if I just want y to get the value assigned but nothing
else (no class, names, dim or other attributes)?
Johann
--
Phone/FAX/Adr/PGPkey ... at http://www.ai.univie.ac.at/~johann