Displaying 20 results from an estimated 10000 matches similar to: "Write protecting objects"
2005 Jul 25
5
passing formula arguments cv.glm
I am trying to write a wrapper for the last example in help(cv.glm) that
deals with leave-one-out-cross-validation (LOOCV) for a logistic model.
This wrapper will be used as part of a bigger program.
Here is my wrapper funtion :
logistic.LOOCV.err <- function( formu=NULL, data=NULL ){
cost.fn <- function(cl, pred) mean( abs(cl-pred) > 0.5 )
glmfit <- glm(
2004 Sep 06
4
substitution in expression
I have been struggling with this problem for a while and I hope someone
could help me. Or if someone could point me to a section in the manual I
would be grateful.
x <- "my"
plot(1:10, main=expression(paste( x, Delta, "values" )))
Q : How do I get the title to say "my (triangle symbol) values" ?
The following trial-and-error produced mainly errors :
2004 Mar 15
2
make check on Solaris 8 fails due to plot
Dear all,
I am having trouble trying to install R-1.8.1 on a Sun Solaris 8
(Generic_108528-23 version) machine. The configuration was successful but
make check fails. I traced the the problem to the plot() function.
> 1 + 1
[1] 2
> capabilities()
jpeg png tcltk X11 GNOME libz http/ftp sockets
TRUE FALSE TRUE TRUE FALSE TRUE TRUE TRUE
2005 Mar 02
5
Differences between package and library terminology
Just out of curiosity, what is the difference between the terms for
package and library ? Why are we loading a package with the library()
command ?
If this is a case of RTFM, I would be happy to do so if pointed in the
right direction. I have searched the FAQ and mail archives and only came
up with http://tolstoy.newcastle.edu.au/R/help/05/02/12162.html but this
still does not explain what is
2004 Oct 01
3
same test statistic for t-test with and without equal variance assumption
Could some kindly tell me if I am supposed to be getting the same test
statistic value with var.equal=TRUE and var.equal=FALSE in t.test ?
set.seed(1066)
x1 <- rnorm(50)
x2 <- rnorm(50)
t.test(x1, x2, var.equal=FALSE)$statistic # 0.5989774
t.test(x1, x2, var.equal=TRUE)$statistic # 0.5989774 ???
Here are my own calculations that shows that perhaps the result when
var.equal=TRUE is
2005 Nov 06
3
How can I assign an argument to transfer whether by ref or by value?
Hello guys,
I am wondering the default way of transferring arguments in R. Is it by
value or by ref in default case, or could that be changed explicitly?
Cheers,
Xiaofan
---
Xiaofan Li
Department of Applied Mathematics and Theoretical Physics
University of Cambridge
2008 Sep 11
9
How to load functions in R
Hello,
I am trying to use self created functions in other scripts than the one
where they are stored.
For the moment I am using the following structure of commands to do
that:
1. Load the text file with the functions in the current script:
x=parse("path")
2. transform the tex in a function: f1=eval(x[1]), f2=eval(x[2]) if more
than one function is stored in the text file
3. use the
2005 Nov 09
5
How to find statistics like that.
Hi there,
Suppose mu is constant, and error is normally distributed with mean 0 and
fixed variance s. I need to find a statistics that:
Y_i = mu + beta1* I1_i beta2*I2_i + beta3*I1_i*I2_i + +error, where I_i is
1 Y_i is from group A, and 0 if Y_i is from group B.
It is large when beta1=beta2=0
It is small when beta1 and/or beta2 is not equal to 0
How can I find it by R? Thank you very much
2007 Jul 24
7
Obtaining summary of frequencies of value occurrences for a variable in a multivariate dataset.
Hi all,
If the question below as been answered before I
apologize for the posting.
I would like to get the frequencies of occurrence of
all values in a given variable in a multivariate
dataset. In short for each variable (or field) a
summary of values contained with in a value:frequency
pair, there can be many such pairs for a given
variable. I would like to do the same for several such
variables.
2002 Jul 15
2
meaning of error message about collinearity
You are using a method that needs to estimate the covariance matrix of all
the variables. If you have 80 variables, there are (80+1)*80/2 = 3240
variances and covariances to estimate. How many data points do you think
you need to do that?
Some people assume the covariance matrix is diagonal (i.e., assuming all the
variables are uncorrelated). Even then you still have 80 variances to
estimate.
2003 Mar 17
4
X11 connection error in web cgi mode only
Dear all,
I am trying to create a web interface using Perl-CGI to call R plots and
to display them.
The following codes works perfectly fine when I copy and paste into the
console directly or if I save it into script.file and then R --no-save <
script.file producing the graphs.
jpeg("graph.jpeg", width=400, height=400)
plot(rnorm(100))
dev.off()
Now, I put the line system("R
2003 Dec 10
3
How to calculate standard error for a vector?
Hi all!
I 'm beginner and i develop a bio-application with VB and i need some
statistic functions!
could i calculate StdError, CoeffOfVariance, SumSquared with R langage? if
yes, what are functions to use?
I need also to use ANOVA and t-test...
Thanks for your help!
Laurent Houdusse
Analyste Programmeur
2002 Dec 10
2
Variance of a single number
Just out of curiosity, can some please explain the following return NA.
x <- 6
var(x)
y <- c( NA, NA, 10000 )
var(y, na.rm=T)
Unless I am seriously misguided, I believe that the variance of a single
number (i.e. a constant) should be zero. Thanks.
Regards, Adai.
2003 Jun 07
3
Error Compiling e1071
Dear all,
I am trying to compile the package e1071 (version 1.3-11) with R CMD
INSTALL. I tried with R 1.7.0 on Redhat Linux 2.4.7-10 and R 1.6.2 on
Linux 2.4.9-34smp but keep getting the same error message during
configure :
WARNING: g++ 2.96 cannot reliably be used with this package. Please use
a different compiler.
Can anyone help me with this or at least point me in the right direction
?
2005 Jul 18
5
colnames
Hi,
I have a matrix with column names starting with a character in [0-9]. After some matrix operations (e.g. copy to another matrix), R seems to add a character 'X' in front of the column name. Is this a normal default behaviour of R? Why has it got this behaviour? Can it be changed? What would be the side effect?
Thank you.
Regards,
Gilbert
[[alternative HTML version deleted]]
2004 Nov 04
2
list files ignoring the case option
Sorry if this is a question more on regular expressions. I am dealing
with several files which have been badly named. For example the files
are given either the extensions txt, TXT or Txt. I wish to select all
those files ending with 'txt' ignoring case.
Here is how I would do it in bash (Redhat FC2) :
touch a1.txt a2.TXT a3.Txt txt.control TXT.control
ls -1 | grep -i
2004 Sep 13
2
calculating memory usage
I am comparing two different algorithms in terms of speed and memory
usage. I can calculate the processing time with proc.time() as follows
but am not sure how to calculate the memory usage.
ptm <- proc.time()
x <- rnorm(1000000)
proc.time() - ptm
I would like to be within R itself since I will test the algorithm
several hundred times and in batch mode. So manually looking up
2005 Feb 25
2
display full form in args
Forgive me for I do not fully comprehend the idea of classes and methods
but I was wondering if someone could help explain why the function args
() behaves the way it does.
Why does args(cut) show the simplified version instead of the more
complete one as in help("cut"). This is true for few other functions
(e.g. plot, rep).
> args(cut)
function (x, ...)
Sometime I can get
2004 Jul 30
2
pairwise difference operator
There was a BioConductor thread today where the poster wanted to find
pairwise difference between columns of a matrix. I suggested the slow
solution below, hoping that someone might suggest a faster and/or more
elegant solution, but no other response.
I tried unsuccessfully with the apply() family. Searching the mailing
list was not very fruitful either. The closest I got to was a cryptic
chunk
2005 Jan 26
3
Still avoiding loops
Dear all,
I have a matrix X with 47 lines and say 500 columns - values are in {0,1}.
I'd like to compare lines.
For that, I first did:
for (i in 1:(dim(X)[1]-1))
for (j in (i+1):dim(X)[1]) {
Y <- X[i,]+Y[j,]
etc.
but, since it takes a long time, I would prefer avoding loops;
for that, my first idea was to add this matrix:
X1=X[,rep(1:46,46:1)]
to this one:
res=NULL
for (i in