Displaying 20 results from an estimated 1255 matches similar to: "Why aov() with Error() gives three strata?"

2017 Dec 28

1

Why aov() with Error() gives three strata?

Jorge:
FYI, *generally speaking,* queries that are mostly statistical in
nature, such as yours, are off topic here -- this list is about R
programming help, not statistical help. Having said that, you still
may get a useful response here -- the r-help/statistics intersection
*is* nonempty. However, if not, 2.5 suggestions:
1. Try posting to r-sig-mixed-models instead. Repeated measures are a

2017 Dec 28

1

Why aov() with Error() gives three strata?

Bert, thanks for the reply but I feel that my question is less about
statistics and more about R interface. Specifically, because the output of
R seems different than other programs (systat, for example, gives a between
and a within table instead of a three level one).
I am familiar with the connection between mixed models and repeated
measures,and how mixed models are essentially replacing the

2017 Dec 29

1

Why aov() with Error() gives three strata?

At any rate:
Error(SUBJECT/IV)
specifies two random effects: SUBJECT and SUBJECT:IV. This is most easily understood if you conceptually arrange your data in a SUBJECT x IV table: One effect is a set of random errors added to each row, the other is a set of effects added to each cell.
If you have more than one observation within each cell, then you need a third set of errors to account for

2008 Dec 04

1

Comparing survival curves with "survdiff" "strata" help

ExpeRts,
I''m trying to compare three survival curves using the function "survdiff" in the survival package. Following is my code and corresponding error message.
> survdiff(Surv(st_months, status) ~ strata(BOR), data=mydata)
Error in survdiff(Surv(st_months, status) ~ strata(BOR), data = mydata) :
No groups to test
When I check the "strata" of the variable. I

2013 Dec 07

2

combine glmnet and coxph (and survfit) with strata()

Dear All,
I want to generate survival curve with cox model but I want to estimate the
coefficients using glmnet. However, I also want to include a strata() term
in the model. Could anyone please tell me how to have this strata() effect
in the model in glmnet? I tried converting a formula with strata() to a
design matrix and feeding to glmnet, but glmnet just treats the strata()
term with one

2005 Oct 27

1

Repost: Examples of "classwt", "strata", and "sampsize" i n randomForest?

"classwt" in the current version of the randomForest package doesn''t work
too well. (It''s what was in version 3.x of the original Fortran code by
Breiman and Cutler, not the one in the new Fortran code.) I''d advise
against using it.
"sampsize" and "strata" can be use in conjunction. If "strata" is not
specified, the class

2011 Jul 10

1

Package "survival" --- Difference of coxph strata with subset?

[code]>require("survival")
> coxph(Surv(futime,fustat)~age + strata(rx),ovarian)
Call:
coxph(formula = Surv(futime, fustat) ~ age + strata(rx), data = ovarian)
coef exp(coef) se(coef) z p
age 0.137 1.15 0.0474 2.9 0.0038
Likelihood ratio test=12.7 on 1 df, p=0.000368 n= 26, number of events= 12
> coxph(Surv(futime,fustat)~age, ovarian, subset=rx==1)

2003 Jan 07

2

Extracting means for given strata from dissimilarity object

Is there a way of extracting mean distance or dissimilarity for a given
strata from a ''dist'' or ''dissimilarity'' object, e.g. extract mean distances
for each species in Anderson''s iris data?
data(iris)
iris.dist<-dist(iris[,1:4])
then what?
Mikkel Grum, PhD
Genetic Diversity Scientist
International Plant Genetic Resources Institute (IPGRI)

2018 May 08

0

Fitting problem for Cox model with Strata as interaction term

Dear All,
I got a warning message "X matrix deemed to be singular" in Cox model with
a time dependent coefficient. In my analysis, the variable "SEX" is a
categorical variable which violate the PH assumption in Cox. I first used
the survSplit() function to break the data set into different time
intervals, and then fit the model. The procedures can be described as
follows:

2011 Jan 25

2

NA replacing

Hello R user,
I have following data frame:
df=data.frame(id=c(1:10),strata=rep(c(1,2),c(5,5)),y=c(
10,12,10,NA,15,70,NA,NA,55,100),x=c(3,4,5,7,4,10,12,8,3,15))
and I would like to replace NA''s with:
instead of first NA tapply(na.exclude(df)$y,na.exclude(df)$strata,sum)[1]*
*7 */tapply(na.exclude(df)$x,na.exclude(df)$strata,sum)[1]
where 7 is the value of x (id=4) in strata 1

2003 Feb 12

2

Various Errors using Survey Package

Hi,
I have been experimenting with the new Survey package. Specifically, I was
trying to use some of the functions on the public-use survey data from NHIS
(2000 Sample Adult file).
Error 1): The first error I get is when I try to specify the complex survey
design.
nhis.design<-svydesign(ids=~psu, probs=~probs, strata=~strata, data=nhis.df,
check.strata=TRUE)
Error in svydesign(ids =

2005 Oct 25

0

Examples of "classwt", "strata", and "sampsize" in randomForest?

Just browsing the documentation, and searching the list came up short... I
have some unbalance data and was wondering if, in a "0" v "1" classification
forest, if these options might yield better predictions when the proportion
of one class is low (less than 10% in a sample of 2,000 observations).
Not sure how to specify these terms... from the docs, we have:
classwt: Priors

2009 Jan 07

0

Frailty by strata interactions in coxph (or coxme)?

Hello,
I was hoping that someone could answer a few questions for me (the background is given below):
1) Can the coxph accept an interaction between a covariate and a frailty term
2) If so, is it possible to
a) test the model in which the covariate and the frailty appear as main terms using the penalized likelihood (for gaussian/t frailties)
b)augment model 1) by stratifying on the variable

2008 Sep 12

2

Fw: Complex sampling survey _ Use of survey package

--------------------------------------------------
From: "Ahoussou Sylvie" <sylvie.ahoussou at antilles.inra.fr>
Sent: Friday, September 12, 2008 9:48 AM
To: "Thomas Lumley" <tlumley at u.washington.edu>
Subject: Re: [R] Complex sampling survey _ Use of survey package
> Thanks for your answer
>
> I think I made a mistake when I recopied the 5 first rows of

2005 Oct 04

2

"Survey" package and NAMCS data... unsure of specification

Hello, all.
I wanted to use the "survey" package to analyze data from the National
Ambulatory Medical Care Survey, and am having some difficulty translating
the analysis keywords from one package (Stata) to the other (R). The data
were collected using a multistage probability sampling, and there are
variables included to identify the sampling units and weights. Documentation
from the

2011 Mar 01

1

glht() used with coxph()

Hi, I am experimenting with using glht() from multcomp package together with
coxph(), and glad to find that glht() can work on coph object, for example:
> (fit<-coxph(Surv(stop, status>0)~treatment,bladder1))
coxph(formula = Surv(stop, status > 0) ~ treatment, data = bladder1)
coef exp(coef) se(coef) z p
treatmentpyridoxine -0.063 0.939 0.161

2005 Mar 04

3

Basic stratification calculations

Hi. I''m a student at SFU in Canada. The basic thing I want to do is
calculate means of different strata. I have 2 vectors. One has the values I
want to take the means from, the other is the four strata I am interested
in. So I essentially want to break up the information vector into the four
strata and calculate four means, one for each stratum. How can I do this in
a reasonable way?

2007 Feb 21

0

GLS models - bootstrapping

Dear Lillian,
I tried to estimate parameters for time series regression using time
series bootstrapping as described on page 434 in Davison & Hinkley
(1997) - bootstrap methods and their application. This approach is based
on an AR process (ARIMA model) with a regression term (compare also with
page 414 in Venable & Ripley (2002) - modern applied statistics with S)
I rewrote the code

2017 Nov 13

1

Bootstrap analysis from a conditional logistic regression

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<https://1drv.ms/u/s!Apkg2VlgfYyDgRAeVIM0nEajx0Fb>
[https://r1.res.office365.com/owa/prem/images/dc-png_20.png]<https://1drv.ms/u/s!Apkg2VlgfYyDgRAeVIM0nEajx0Fb>
Screenshot 2017-11-12

2007 Apr 17

1

PROC DISCRIM vs. lda( ) in MASS

Hello,
I am using WinXP, R version 2.3.1, and SAS for PC version 8.1.
I have mostly used SAS over the last 4 years and would like to
compare the output of PROC DISCRIM to that of lda( ) with respect
to a very specific aspect. My data have k=3 populations and there
are 3 variates in the feature space. When using using the code
PROC DISCRIM DATA = FOO OUT = FOO_OUT OUTSTAT = FOOSTAT