Displaying 20 results from an estimated 130 matches similar to: "Linear models and a simple time series"
2012 Aug 17
1
Linear mixed model using R
Dear all,
I am trying to use R to fit mixed models.
Take the following example, where ind is a random effect and
sample is fixed. I wanted to fit
Model 1: values = ind + sample
Model 2: values =ind * sample
Model 3: values=ind(sample) + sample
Tried to use the below for mod1, but it did not work. Can anyone give
some help on this. Thanks so much.
mod1 <- lme(values ~ sample +
2012 Aug 17
3
Apply a function according to factor levels.
Dear all,
I have a question on applying a function to the data according to factor
levels.
For example, for the data below, what is the best way to apply a function
to
"values" according to different levels of "samples" (1,2,3,4,5)?
values ind sample
1 0.03325 1 1
2 0.03305 1 1
3 0.03185 1 1
4 0.03515 1 1
5 0.03375 1 1
6 0.01180
2009 Aug 13
1
prop.test() - need algorithm or reference
Preparing a paper for a medical journal.
Using the prop.test() function in R (v2.4.0)
to compare two groups' response to data like the following.
A sample of 100 individuals from Population I, 18 with positive readings
from a certain test,
vs.
A sample of 148 individuals from Population II, 61 with positive readings.
Results look like this:
R version 2.4.0 Patched (2006-11-25
2008 Dec 23
1
newbie problem using Design.rcs
Hi,
I read data from a file. I'm trying to understand how to use Design.rcs by using simple test data first. I use 1000 integer values (1,...,1000) for x (the predictor) with some noise (x+.02*x) and I set the response variable y=x. Then, I try rcs and ols as follows:
m = ( sqrt(y1) ~ ( rcs(x1,3) ) ); #I tried without sqrt also
f = ols(m, data=data_train.df);
print(f);
[I plot original
2009 Dec 24
2
Locating code that is outside of functions in R scripts
Working with a number of scripts (text files with R commands) that I
"source" into R sessions from time to time.
The source() command is most convenient (at least for me)
if it only loads function definitions, and doesn't otherwise change the
interactive environment. For example, I might have a file that looks like
func1<-function() {
code
code
code
}
# this
2005 Aug 08
1
get the wald chi square in binary logistic regression
hello,
I work since a few time on R and i wanted to know how to obtain the Wald chi
square value when you make a binary logistic regression. In fact, i have the z
value and the signification but is there a script to see what is the value of
Wald chi square. You can see my model below,
Best regards,
S??verine Erhel
[Previously saved workspace restored]
> m3 = glm(reponse2 ~ form +
2011 Oct 22
5
interpreting bootstrap corrected slope [rms package]
Dear List:
Below is the validation output of a fitted ordinal logistic model
using the bootstrap in the rms package. My interpretation is that
most of the corrected indices indicate little overfitting, however the
slope seems to indicate that the model is too optimistic. Given that
most of the corrected indices seem reasonable, would it be appropriate
to use this model on future data if the
2011 Sep 19
0
nls picewise FvCB model
Greetings R users, maybe there is someone who can help me with this problem:
I'm trying to fit this discontinous model :
GE<-data.frame( Ci<-c(81,87,91,111,159,173,295,453,629,984),
A<-c(-0.9,1.2,3.5,8.3,13.1,14.4,22.9,27.3,29.6,32.6) )
rhs <- function(Ci, Vcmax, J, Rd) {
? ?R <-0.008314472
? ?Tleaf <-25
? ?Kc <-exp(38.05-79.43/(R*(Tleaf+273.15)))
? ?Ko
2011 Oct 11
3
Chi-Square test and survey results
An organization has asked me to comment on the validity of their
recent all-employee survey. Survey responses, by geographic region,
compared
with the total number of employees in each region, were as follows:
> ByRegion
All.Employees Survey.Respondents
Region_1 735 142
Region_2 500 83
Region_3 897 78
2016 Apr 26
5
From NUM to INT
Dear all:
I converted the columns (Baci, Meti, Fungii, Protozoai) into integers
(using excel) and then imported the data (.txt) into R. Interestingly, the
other three variables were loaded as INT, but the 'Baci' one continued as
Num.
I imported the data using the following command line:
X <- read.delim(file.choose(),
header = TRUE,
dec =
2009 Oct 07
0
error using predict() / "fRegression"-package
Hello!
I'm puzzled by the following problem. It occurs while trying to predict
responses in a test-dataset using a linear model fitted with regFit from
the rMetrics "fRegression"-package.
All goes well when I call "predict" using the training dataset. However,
a call using the test-dataset retuns an error message - telling me that
the latter dataset provides variables
2009 Sep 02
0
Cointegration/urca package
Hello!
I estimate vector error correction model (vecm) model. I have only one cointegratio relationship. I write :
joh.vecm.rls <- cajorls(joh.vecm, r=1)
The output estimation is :
Call:
lm(formula = substitute(form1), data = data.mat)
Coefficients:
up.d expl.d upd.d r.d
ect1 -1.34e-01 4.55e+02 6.91e+00 2.43e+03
constant
2003 Sep 30
0
lme vs. aov
Hi,
I have a question about using "lme" and "aov" for the
following dataset. If I understand correctly, using
"aov" with Error term in the formula is equivalent to
using "lme" with default settings, i.e. both assume
compound symmetry correlation structure. And I have
found that equivalency in the past. However, with the
follwing dataset, I got different
2003 Oct 02
0
lme vs. aov with Error term
Hi,
I have a question about using "lme" and "aov" for the
following dataset. If I understand correctly, using
"aov" with an Error term in the formula is equivalent
to using "lme" with default settings, i.e. both assume
compound symmetry correlation structure. And I have
found that equivalency in the past. However, with the
follwing dataset, I got different
2003 Oct 01
0
lme vs. aov with Error term again
Hi all,
Sent the following question yesterday, but haven't got
any suggestions yet. So just trying again, can anyone
comment on the problem that I have? Thank you!
-------------
Hi,
I have a question about using "lme" and "aov" for the
following dataset. If I understand correctly, using
"aov" with an Error term in the formula is equivalent
to using
2011 Jul 13
1
AR-GARCH with additional variable - estimation problem
Dear list members,
I am trying to estimate parameters of the AR(1)-GARCH(1,1) model. I have one
additional dummy variable for the AR(1) part.
First I wanted to do it using garchFit function (everything would be then
estimated in one step) however in the fGarch library I didn't find a way to
include an additional variable.
That would be the formula but, as said, I think it is impossible to add
2003 Oct 02
0
RE: [S] lme vs. aov with Error term
Hi Bert,
Thanks for the suggestions. I tried lme with different
control parameters, and also tried using "ML", instaed
of "REML", but still got the same answers.
Yes, I hope some gurus on this list could give me some
hints.
Thanks
--- "Gunter, Bert" <bert_gunter at merck.com> wrote:
> But they are close. This is almost certainly a
> numeric issue --
2016 Apr 26
2
From NUM to INT
Ok. I`m trying to run a Poisson glmm with an observation-level random
intercept. But I`m getting the following error for the 'Baci' variable:
'Error: (maxstephalfit) PIRLS step-halvings failed to reduce deviance in
pwrssUpdate'. I guess this message is because the baci variable is not a
an integer, and cannot be transformed into an integer as R has a threshold
of
2x10^9 even in
2008 Oct 16
2
Missing something about sendmail
Hi All,
I have a strange problem that I don't understand. I have an access file
which has the following line:
168.144.250.215 OK # xsmtp02.mail2web.com
Yet email from this IP address is getting rejected. From my log file
Oct 15 21:52:33 mx01 sendmail[10569]: ruleset=check_relay,
arg1=xsmtp02.mail2web.com, arg2=168.144.250.215,
relay=xsmtp02.mail2web.com
2010 Oct 29
0
Re: In the process of deciding to virtualize, manyuncertainties
Thx Rudi,
I tried but the mirrors citrix and citrix/primary give error : no package
make available. Not sure if I can configure another download server.
Harry
Original Message:
-----------------
From: Rudi Ahlers Rudi@SoftDux.com
Date: Fri, 29 Oct 2010 16:52:29 +0200
To: harry@aasterud.com, xen-users@lists.xensource.com
Subject: Re: [Xen-users] In the process of deciding to