Displaying 18 results from an estimated 18 matches similar to: "How can I 'predict' from an nls model with a fit specified for separate groups?"
2006 Nov 29
3
R2.4 xyplot + panel.number problem
Hi all;
I'm trying to display a 2 panel plot for the Puromycin data from R
with 2 different non-linear models fitted to each group. The problem
is that as far as I know panel.number doesn't work in the latest
version of R. Can anyone give a hint how to solve this?
Here is the code that I used before and now doesn't work
xyplot(rate ~conc| state,Puromycin,
2003 Oct 28
2
Confidence ellipse for correlation
Hello,
SAS' point and click interface has the option of produce a scatterplot with a
superimposed confidence ellipse for the correlation coefficient. Since I
generally like R so much better, I would like to reproduce this in R. I've
been playing with the ellipse package. In order to have the points and the
ellipse on the same graph I've done the following.
(Load ellipse
2009 Nov 17
1
Define lm/glm object without evaluating them
For e.g. lm/glm type models I would like to separate model specification and model fitting and then only fit the models later 'when data arrives'. To be specific, I would like make a specification like
m1 <- lm(rate~conc)
m2 <- lm(rate~I(conc^2))
and then later I want to 'put data into' the objects and evaluate (fit the model), e.g. something like
update(m1, data=Puromycin)
2008 Nov 03
2
standard errors for predict.nls?
Dear all,
Is there a way to retrieve standard errors from nls models? The help page tells me that arguments
such as se.fit are ignored...
Many thanks and best wishes
Christoph
--
Dr. rer.nat. Christoph Scherber
University of Goettingen
DNPW, Agroecology
Waldweg 26
D-37073 Goettingen
Germany
phone +49 (0)551 39 8807
fax +49 (0)551 39 8806
Homepage http://www.gwdg.de/~cscherb1
2003 Oct 30
2
'nls' and its arguments
Dear R experts!
I'd to fit data by 'nls' with me-supplied function 'fcn'.
1) I'd like 'fcn' to accept arbitrary arguments, i.e. I defined it
as f(...) {<body>}. (Ok, that's not actually impotant).
2) Second, I would NOT like to supply every parameter in the formula.
To illustrate this, let's look at the last example of 'nls' help
2004 May 21
1
Buglet/omission in nls package (PR#6901)
Dear all,
I noticed the following under R 1.8.1 (when nls was still a separate
package) but the same problem occurs under R 1.9.0 (where most (all?)
of nls is now in the stats package):
> data(Puromycin)
> fm <- nls(rate~SSmicmen(conc,b0,b1), Puromycin, subset = state=="treated")
> coef(summary(fm))
NULL
The problem seems to be that summary.nls uses the name
2005 Jul 11
2
Weighted nls
Dear R Community,
I am attempting to perform a weighted non-linear least squares fit. It has already been noted that the weights option is not yet implemented for the nls function, but no one seems to offer any suggestions for getting around this problem. I am still curious if a) anyone has code they have written which includes a weight options for nls, or b) if there is another model which
2004 Nov 08
2
Nonlinear weighted least squares estimation
Hi there,
I'm trying to fit a growth curve to some data and need to use a weighted least squares estimator to account for heteroscedasticity in the data. A weights argument is available in nls that would appear to be appropriate for this purpose, but it is listed as 'not yet implemented'. Is there another package which could implement this procedure?
Regards,
Robert Brown
2007 Jun 07
2
Nonlinear Regression
Hello
I followed the example in page 59, chapter 11 of the 'Introduction to R'
manual. I entered my own x,y data. I used the least squares. My function has
5 parameters: p[1], p[2], p[3], p[4], p[5]. I plotted the x-y data. Then I
used lines(spline(xfit,yfit)) to overlay best curves on the data while
changing the parameters. My question is how do I calculate the residual sum
of squares.
2004 Feb 02
1
Robust nonlinear regression - sin(x)/x?
You reall have only one parameter in your model, c = a/b. You can't
identify both a and b from your model, therefore, you should fit the
linear model: lm(z ~ c* sin(x)/x)
Ravi.
----- Original Message -----
From: cstrato <cstrato at aon.at>
Date: Monday, February 2, 2004 2:28 pm
Subject: [R] Robust nonlinear regression - sin(x)/x?
> Dear all
>
> Since I did not receive any
2010 Jan 29
1
Step function
Hi All,
Does the step function work in this model? I tried to run the
following model but no result obtained. The computer is hanging and I
killed the job several times. Below is the code.
library(survival)
m.fit=clogit(y~x1+x2+x3+x4, data=ftest)
summary(m.fit)
final<- step(m.fit)
Thanks in advance.
2005 Feb 02
4
(no subject)
can you recommend a good manual for R that starts with a data set and gives
demonstrations on what can be done using R? I downloadedR Langauage
definition and An introduction to R but haven't found them overly useful.
I'd really like to be able to follow some tutorials using a dataset or many
datasets. The datasets I have available on R are
Data sets in package 'datasets':
2003 Nov 19
11
Windows R 1.8.0 hangs when Mem Usage >1.8GB
I have a loop that increases the size of an object after each iteration. When the Windows Task Manager shows "Mem Usage" about 1.8GB, the Rgui.exe process no longer responds.
I use:
"C:\Program Files\R\rw1080\bin\Rgui.exe" --max-mem-size=4000M --min-vsize=10M --max-vsize=3000M --min-nsize=500k --max-nsize=1000M
I have a dual Xeon 2.8GHz processor box with 4GB of memory and
2005 May 24
0
R Packages and code published in JSS in 2005
Get articles from http://www.jstatsoft.org
Firth
Bradley-Terry Models in R
Volume 12, Issue 01
Sturtz, Ligges, and Gelman
R2WinBUGS: A Package for Running WinBUGS from R
Volume 12, Issue 03
Mineo and Ruggieri
A Software Tool for the Exponential Power Distribution: The normalp
Package
Volume 12, Issue 04
Ritz and Streibig
Bioassay Analysis Using R
Volume 12, Issue 05
Baddeley and Turner
2005 May 24
0
R Packages and code published in JSS in 2005
Get articles from http://www.jstatsoft.org
Firth
Bradley-Terry Models in R
Volume 12, Issue 01
Sturtz, Ligges, and Gelman
R2WinBUGS: A Package for Running WinBUGS from R
Volume 12, Issue 03
Mineo and Ruggieri
A Software Tool for the Exponential Power Distribution: The normalp
Package
Volume 12, Issue 04
Ritz and Streibig
Bioassay Analysis Using R
Volume 12, Issue 05
Baddeley and Turner
2009 Nov 12
0
writing selfStart models that can deal with treatment effects
Hello,
I'm trying to do some non-linear regression with 2 cell types and 4 tissue
type treatments using selfStart models
Following Ritz and Streibig (2009), I wrote the following routines:
##Selfstart
expDecayAndConstantInflowModel <- function(Tb0, time, aL, aN, T0){
exp(-time*aL)*(T0*aL+(-1+exp(time * aL))*Tb0 * aN)/aL
}
expDecayAndConstantInflowModelInit <- function(mCall, LHS,
2002 Jul 11
1
dyn.load tcl/tk (PR#1774)
<<insert bug report here>>
------------------------------------------------------
Error:
R : Copyright 2002, The R Development Core Team
Version 1.5.1 (2002-06-17)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type `license()' or `licence()' for distribution details.
R is a collaborative project with
2000 Feb 17
2
Installation of rpm file on Suse Linux 6.2 (PR#449)
Full_Name: Luzi P. Schucan
Version: R-base-0.90.1-2.i386.rpm
OS: Linux
Submission from: (NULL) (141.84.136.129)
I just wanted to install the rpm package with rpm --v -i [file], and here is the
log:
(I DID run it as root!!)
(the important thing is in the end: there must be a bug in the post install
script.
The problem is, that it does install all the files, but it doesn't correctly
hang
the