Displaying 20 results from an estimated 1000 matches similar to: "How to calculate standard error for a vector?"
2004 Aug 13
5
simtest for Dunnett's test
Hi!
I use simtest fonction of multcomp package to compile a Dunnett's test.
I have 10 treatments and one control group, so i create a matrix with:
m<-matrix(0,10,11)
m[1,1]<--1
m[1,2]<-1
m[2,1]<--1
m[2,3]<-1
m[3,1]<--1
m[3,4]<-1
m[4,1]<--1
m[4,5]<-1
m[5,1]<--1
m[5,6]<-1
m[6,1]<--1
m[6,7]<-1
m[7,1]<--1
m[7,8]<-1
m[8,1]<--1
m[8,9]<-1
2004 Jan 23
5
Levels number of a factor object
Hi all!
How to retrieve the levels number of a factor object?
See this code:
groups<-gl(4,10)
I want to retrieve the number of levels (4) of my object "groups"
I tried groups.levels but this don't work
Thanks
Laurent Houdusse
Analyste Programmeur
2004 Feb 04
5
nortest package
Hi,
I'm a newbie and i am unable to use lillie.test in nortest
I have a message: "Couldn't find function "lillie.test"
I am under windows2000 with R1.8.1
nortest is listed with .packages(TRUE)
How to do to use lillie.test function?
Laurent Houdusse
Analyste Programmeur
2004 Jan 27
2
Probability for ANOVA
Hi all!
I have 4 treatments on 5 animals
Treat1 Treat2 Treat3 Treat4
Animal1 36 37 35 39
Animal2 33 34 36 37
Animal3 37 35 33 38
Animal4 34 36 34 35
Animal5 35 36 33 36
I use an Anova and i try to verify calcul
So i retrieve:
DF SS
2004 Feb 06
2
Normality Test on several groups
Hi,
I use ks.test or lillie.test to verify a normal distribution. It's performed
for a group
My users use SigmaStat software and a One Way ANOVA on several groups
In the result page there is a probability value to determine if Normality
test is failed or passed
So, how can i retrieve this probability value on several groups?
Is there another function in R to verify normality on several
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 :
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(
2003 Nov 21
3
speeding up a pairwise correlation calculation
Hi,
I have a data.frame with 294 columns and 211 rows. I am calculating
correlations between all pairs of columns (excluding column 1) and based
on these correlation values I delete one column from any pair that shows
a R^2 greater than a cuttoff value. (Rather than directly delete the
column all I do is store the column number, and do the deletion later)
The code I am using is:
ndesc
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 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
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
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
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
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.
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
2004 Aug 06
1
About the number of channels
Is it possible to encode/decode more than 2 channels (stereo) stream
with Speex ?
We are currently recording one,two or four channels stream and we had to
customize an ADPCM codec for the four channels part.
------------------------
Stéphane Laliberté
Analyste-Programmeur
Novo Technologie inc.
<p>--- >8 ----
List archives: http://www.xiph.org/archives/
Ogg project homepage:
2003 Sep 15
1
User permissions on samba shared directories
Hi everybody,
I have successfully installed and configured Samba on my Aix box. I have setup domain security and mounted the machiine on the domain. I added a [homes] section and now everybody logging to their Windows 2000 workstations have access to their Aix home directory, what is great!
However, I have noticed by checking the home directory security for my user that there is THREE users |
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
?