Displaying 20 results from an estimated 10000 matches similar to: "using lme on multiple datasets in one shot"
2007 Jul 25
2
using contrasts on matrix regressions (using gmodels, perhaps)
Hi,
I want to test for a contrast from a regression where I am regressing the columns of a matrix. In short, the following.
X <- matrix(rnorm(50),10,5)
Y <- matrix(rnorm(50),10,5)
lm(Y~X)
Call:
lm(formula = Y ~ X)
Coefficients:
[,1] [,2] [,3] [,4] [,5]
(Intercept) 0.3350 -0.1989 -0.1932 0.7528 0.0727
X1 0.2007 -0.8505 0.0520
2012 Mar 19
1
car/MANOVA question
Dear colleagues,
I had a question wrt the car package. How do I evaluate whether a
simpler multivariate regression model is adequate?
For instance, I do the following:
ami <- read.table(file =
"http://www.public.iastate.edu/~maitra/stat501/datasets/amitriptyline.dat",
col.names=c("TCAD", "drug", "gender", "antidepressant","PR",
2007 May 18
2
displaying intensity through opacity on an image
Dear colleagues,
I have an image which I can display in the greyscale using image. On this image, for some pixels, which I know, I want to display their activity based on a third measure. One way to do that would be to color these differently, and use an opacity measure to display the third measure. An example of what I am trying to do is at:
2011 Mar 20
3
manova question
Dear friends,
Sorry for this somewhat generically titled posting but I had a question
with using contrasts in a manova context. So here is my question:
Suppose I am interested in doing inference on \beta in the case of the
model given by:
Y = X %*% \beta + e
where Y is a n x p matrix of observations, X is a n x m design matrix,
\beta is m x p matrix of parameters, and e is a
2007 Mar 21
3
question on suppressing error messages with Rmath library
Dear list,
I have been using the Rmath library for quite a while: in the current instance, I am calling dnt (non-central t density function) repeatedly for several million. When the argument is small, I get the warning message:
full precision was not achieved in 'pnt'
which is nothing unexpected. (The density calls pnt, if you look at the function dnt.) However, to have this happen a
2012 May 07
1
commenting out a block of R code
Dear friends,
Is there an easy way of commenting out a block of R code after it has
been written? (I am aware that R-aware editors can insert #
line-by-line while it is being written, but I want to basically block
out chunks of R code in a few strokes.)
This question was asked on this mailing list some time ago: Professor
Ripley's answer was to try the following:
2011 Apr 12
1
Using help in Windows version of R with disabled browser
Dear colleagues,
I am trying to get someone to use R on MS Windows with the browser
disabled. My question is how does he/she get to use R-help which goes
off the browser (and correspondingly complains about the inability to
start firefox, etc). In linux, which is what I use, this is not a
problem: what needs to be set in Windows to replicate this behavior?
Sorry if I am not clear: please feel
2012 Jun 21
1
R function similar to gradient function in Matlab?
Hi,
I am trying to convert some Matlab code into R for running some
experiments and I was wondering if there is some function in R which
does the work of the gradient function in Matlab calculating the
"gradient" of 1-, 2- and 3-d images. I only need the 3-d calculations
for running these experiments.
Many thanks and best wishes,
Ranjan
2025 May 20
2
how to read a PSB file in R?
On Tue May20'25 05:56:59AM, Rui Barradas wrote:
> From: Rui Barradas <ruipbarradas at sapo.pt>
> Date: Tue, 20 May 2025 05:56:59 +0100
> To: Ranjan Maitra <mlmaitra at gmx.com>, r-help at r-project.org
> Subject: Re: [R] how to read a PSB file in R?
>
> ?s 03:17 de 20/05/2025, Ranjan Maitra via R-help escreveu:
> > I have come across this file (warning,
2017 Aug 24
1
Scaling Matrix in qda() function in MASS package
I guess the question that is being asked here is what is the scaling matrix that is being returned in the qda object. The help file on qda() says:
...
scaling: for each group ?i?, ?scaling[,,i]? is an array which transforms observations so that within-groups covariance matrix is spherical.
...
This is a bit ambiguous. I tried a few cases (spectral, QR decomposition, especially given that it is an
2001 Feb 23
4
hclust question
Dear all,
I have a question with regard to the use of hclust. I would like to be
able to specify my own distance matrix instead of asking R to compute
the distance matrix for me. It is computationally easier for me this
way. My question is: How can I get hclust to accept this?
Thanks,
Ranjan
--
***************************************************************************
Ranjan
2018 Mar 30
0
getting all circular arrangements without accounting for order
I don't know if this is more efficient than enumerating with distinct
directions and weeding... it seems kind of heavyweight to me:
#######
library(gtools)
directionless_circular_permutations <- function( n ) {
v <- seq.int( n-1 )
ix <- combinations( n-1, 2 )
jx <- permutations( n-3, n-3 )
x <- lapply( seq.int( nrow( ix ) )
, function( i ) {
2025 May 26
1
how to read a PSB file in R?
On Tue May20'25 12:15:41AM, Ranjan Maitra via R-help wrote:
> From: Ranjan Maitra via R-help <r-help at r-project.org>
> Date: Tue, 20 May 2025 00:15:41 -0500
> To: r-help at r-project.org
> Reply-To: Ranjan Maitra <mlmaitra at gmx.com>
> Subject: Re: [R] how to read a PSB file in R?
>
> On Tue May20'25 05:56:59AM, Rui Barradas wrote:
> > From: Rui
2018 Mar 30
2
getting all circular arrangements without accounting for order
Jeff,
I wanted to let you know that your function is faster than generating the directional circular permutations and weeding.
Here is the time for n = 10. I compared with just doing the permutations, there is no point in proceeding further with the weeding since it is slower at the start itself.
system.time(directionless_circular_permutations(10))
user system elapsed
1.576 0.000
2018 Mar 30
3
getting all circular arrangements without accounting for order
Thanks!
Yes, however, this seems a bit wasteful. Just wondering if there are other, more efficient options possible.
Best wishes,
Ranjan
On Thu, 29 Mar 2018 22:20:19 -0400 Boris Steipe <boris.steipe at utoronto.ca> wrote:
> If one is equal to the reverse of another, keep only one of the pair.
>
> B.
>
>
>
> > On Mar 29, 2018, at 9:48 PM, Ranjan Maitra
2018 Jan 18
1
reading lisp file in R
Thanks! I am trying to use it in R. (Actually, I try to give my students experiences with different kinds of files and I was wondering if there were tools available for such kinds of files. I don't know Lisp so I do not actually know what the lines towards the bottom of the file mean.(
Many thanks for your response!
Best wishes,
Ranjan
On Wed, 17 Jan 2018 20:59:48 -0800 David Winsemius
2018 Mar 30
0
getting all circular arrangements without accounting for order
New function below is a bit faster due to more efficent memory handling.
for-loop FTW!
directionless_circular_permutations2 <- function( n ) {
n1 <- n - 1L
v <- seq.int( n1 )
ix <- combinations( n1, 2L )
jx <- permutations( n-3L, n-3L )
jxrows <- nrow( jx )
jxoffsets <- seq.int( jxrows )
result <- matrix( n, nrow = factorial( n1 )/2L, ncol = n )
k
2018 Jan 18
0
reading lisp file in R
> On Jan 17, 2018, at 8:22 PM, Ranjan Maitra <maitra at email.com> wrote:
>
> Dear friends,
>
> Is there a way to read data files written in lisp into R?
>
> Here is the file: https://archive.ics.uci.edu/ml/machine-learning-databases/university/university.data
>
> I would like to read it into R. Any suggestions?
It's just a text file. What difficulties
2025 May 20
1
how to read a PSB file in R?
?s 03:17 de 20/05/2025, Ranjan Maitra via R-help escreveu:
> I have come across this file (warning, massive, 4.3 GB) https://esahubble.org/media/archives/images/original/heic1502a.psb and it appears to be a filetype I was not aware of previously.
>
> Is it possible to read the file in R using any tool? It is an image and I am looking for the RGB of the file.
>
> Many thanks and
2018 Mar 30
0
getting all circular arrangements without accounting for order
If one is equal to the reverse of another, keep only one of the pair.
B.
> On Mar 29, 2018, at 9:48 PM, Ranjan Maitra <maitra at email.com> wrote:
>
> Dear friends,
>
> I would like to get all possible arrangements of n objects listed 1:n on a circle.
>
> Now this is easy to do in R. Keep the last spot fixed at n and fill in the rest using permuations(n-1, n-1)