Displaying 20 results from an estimated 10000 matches similar to: "discriminate analysis"
2001 Aug 28
2
using by to plot
Hello,
I would like to use by to create a series of plots, but I'm not sure how
to design the function.
Here's what I've got:
1. A data frame of observations of measured value 2 measured vlaues and a
pch code.
V1 V2 pchCode
.0045 123 1
.0034 145 2
.0045 123 1
.0046 167 3
...
So what I want to do is create a single scatterplot of the multiple
conditions (specified by
2001 Jul 20
4
plotting dendrograms
Hello,
Can anyone offer any insight on graphing classification dendrograms with
the nodes marked?
plot(tree()) produces a nice tree structure but there's no acccompanying
text.
Thanks,
D
S. David White
sdavidwhite at bigfoot.com
Columbus, Ohio
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r-help mailing list -- Read
2003 Mar 31
2
Does R have an inverse wishart distribution?
If so, I''ve had trouble finding it. Can anyone help?
2000 Mar 22
3
segmentation fault with 1D array (PR#500)
Here's a nasty one. The following has caused a segmentation
fault and possibly also a bus error.
fred <- 1:6
dim(fred) <- 6
dimnames(fred) <- list(LETTERS[1:6])
mm <- matrix(1:12, 2, 6)
mm %*% fred # segmentation fault here
In the case without the dimnames assignment the result is OK.
Cheers, Jonathan.
--please do not edit the information below--
Version:
platform =
2003 Sep 30
2
truncated multivariate normal
Please,
I would like to know how to generate a truncated multivariate normal
distribution k - dimensional, X ~ NT(mu, Sigma), where the
elements of X to be non-negative (except the first), and the first
dimension is strictly larger than zero.
Example:
X ~ NT_2(mu, Sigma),
where mu=c(0.5, 0.5) and Sigma=c([120, 191], [191,154]), with X_1>0
and X_2>=0
Could anybody help
2003 Sep 26
3
Std. errors of intercept and slope
Dear all,
I have the following output generated by linear regression. Since there is
only one regression intercept and one slope for one set of data, what is the
meaning of std. error for intercept and that of slope? Thanks in advance.
Sincerely,
Minghua
> data(thuesen)
> attach(thuesen)
> lm(short.velocity~blood.glucose)
Call:
lm(formula = short.velocity ~ blood.glucose)
2002 Feb 20
2
Code for bivariate Poisson regression?
Dear RHelpers,
Does anyone know of any R code to perform bivariate Poisson regression
(including random effects)?
Best wishes
Simon
Simon D.W. Frost, M.A., D.Phil.
Department of Pathology
University of California, San Diego
Antiviral Research Center
(Formerly: UCSD Treatment Center)
150 W. Washington St., Suite 100
San Diego, CA 92103
USA
Tel: +1 619 543 8080 x275
Fax: +1 619 298 0177
Email:
2001 Nov 29
2
plotting (a) confidence intervals (b) standard error
Hi all,
I'm building a plot of the values in tmeant (below) against positions 1 to
5, using matplot.
tmeant looks like this:
case1 case2
pos1 861.8466 818.5909
pos2 961.2841 976.3466
pos3 878.6080 1262.8523
pos4 950.8011 1129.6080
pos5 968.1080 1063.3920
I also have lower (object tl) and upper (object tu) bounds on the
confidence intervals as follows:
tl:
pos1
2003 Mar 21
5
manipulating "..." inside a function
Dear R-help,
Can some one tell me how to do the following (if it's possible)?
Suppose I have a function like this:
f <- function(x, y, ...) {
## some code
g(x, y, ...)
## some more code
}
The problem is that g() may not understand everything that comes through in
"...". Is there a way to delete some component of "..." and then pass it to
g()?
Here's
2003 Nov 05
3
using LSODA in R
R help list subscribers,
I am a new user of R. I am attempting to use R to explore a set of
equations specifying the dynamics of a three trophic level food chain. I
have put together this code for the function that is to be evaluted by
LSODA. My equations Rprime, Cprime, and Pprime are meant to describe the
actual equation of the derivative. When I run LSODA, I do not get the
output that
2001 Oct 29
2
write a bunch of objects to files
Hello all,
I've got a bunch of objects I'd like to write to .csv files. For example,
I have objects conveniently called
n002.csv
n001.csv
p103.csv
.
.
.
I tried a loop:
> for(i in ls(pattern="csv"))
+write.table(i, file=i, sep=",", quote=F)
That, of course, wrote out a bunch of files that contained
x
1, n002.csv
Or the like.
How can I get i in the loop above
2006 Jun 29
3
advice on arguments
I have a general style question about R coding.
Suppose I'm writing a function (foo1) that calls other functions
(foo2, foo3, ...) which have complicated argument
lists (e.g. optim(), plot()), _and_
I may be calling several different functions in the body of
foo1. Since foo2 and foo3 have different sets of arguments, I
can't just use "..." ; I did write some code a while ago
2000 Oct 03
3
prcomp compared to SPAD
Hi !
I've used the example given in the documentation for the prcomp function
both in R and SPAD to compare the results obtained.
Surprisingly, I do not obtain the same results for the coordinates of
the principal composantes with these two softwares.
using USArrests data I obtain with R :
> summary(prcomp(USArrests))
Importance of components:
PC1 PC2
2002 Dec 17
4
Quick tip please!
I have two CSV files (exported from Excel), say file1 and file2.
The have the same number of rows, and each has several columns,
with names on the first line; and some of the columns in file1
are repeated in file2.
Using the "foreign" package, I can read these in separately
to dataframes say d1 and d2 with
> d1<-read.csv("file1")
>
2002 Oct 11
4
read.table( ... comment.char="#") truncated my data
Dear all,
I found that the new feature of the comment.char="#" argument in the
read.table function truncated my data while the data set actually contains
'#'. We analyze lot of data that contain '#'. This is really annoying and
it is also not compatible earlier version of R. I searched the R archive
and found the following message for the scan function. Is it
2003 Jan 28
6
reading non-existent files
Dear R-experts
I would like to read all files from a directory, the files have names
"myname0001.txt" etc. I paste the directory plus file names and
use "read.delim()".
My problem is that some file names are missing, so I get an error
and my program stops.
Is there a way to check for a null pointer analogous to C, so that
I can simply skip non-existent filenames?
Please do
2003 Feb 28
1
Error bars for interaction plots
How do I add error bars to an interaction plot of means?
Thanks
2002 Dec 05
1
How to plot a 3D ellipsoid in R?
Hey, all
I am going to plot several 3-dimensional ellipsoids
in R.
For example, A is such a ellipsoid with
mean u=[1 1 1]', covariance matrix C=[1 0 .5;0 1 .6;.5 .6 1];
So how can I plot such object in 3D space?
Is there some function to achieve this?
Thanks.
Fred
2002 Dec 15
3
maximum likelihood example?
I'm trying to get a grasp of maximum-likelihood estimation and would like to
find a package that performs mle (hopefully a simple example). It seems as
if there are plenty of packages that make use of different types of
likelihood estimators, but none are of a simple, "newbie" type. Does anyone
have a suggestion for which package would be the best for a mle example?
Thanks,
Jeff.
2002 Mar 12
1
using R API in dynamically loaded code?
I'm probably missing something very basic here, but:
I've written some C code that I load into R dynamically. In the course
of this C code, I generate some multinomial random deviates. I initially
used the publically available "randlib" library, which also implements
its own random number generator and binomial deviates (which are used to
generate the multinomial deviates).