Displaying 20 results from an estimated 285 matches for "litter".
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2004 May 29
1
multiple nesting levels in GEE
Hello,
I'm actually trying to fit a gee model with 2 nesting levels since I expect a
correlation between all members of a litter at a first level and between all
individuals sharing a mother at a second superior level with an exchangeable
matrix. I order my dataframe by both mother and litter
I try several syntaxes:
id= mother*litter which give the same correlation matrix as id= litter*mother
and id=litter with a matrix s...
2004 Aug 20
1
drop1 with contr.treatment
...st.
Another possibility is to produce a warning when you use drop1
with the scope argument to get main effects in the presence of
an interaction (even not signifikant) with "treatment"
contrast.
An example:
library(MASS)
##- Data "genotype"
names(genotype)
##- > [1] "Litter" "Mother" "Wt"
##- to be sure the contrasts are "treatment"
options(contrasts = c("contr.treatment", "contr.poly" ))
##- model with interaction
gen.int <- aov(Wt ~ Litter*Mother, data = genotype)
drop1(gen.int, scope = .~., test = "F&...
2002 Jun 21
1
lme: anova vs. intervals
...tive?
Partial output follows.
Thanks for the insight.
Hank
> anova(fm0)
numDF denDF F-value p-value
(Intercept) 1 69 6331.902 <.0001
Fert 3 44 42.176 <.0001
Seed 1 44 0.488 0.4886
Litter 1 69 1.830 0.1805
Density 1 69 68.714 <.0001
Fert:Seed 3 44 0.061 0.9799
Fert:Litter 3 69 0.294 0.8294
Fert:Density 3 69 0.381 0.7667
Seed:Litter 1...
2011 Jun 25
2
cluster() or frailty() in coxph
Dear List,
Can anyone please explain the difference between cluster() and
frailty() in a coxph? I am a bit puzzled about it. Would appreciate
any useful reference or direction.
cheers,
Ehsan
> marginal.model <- coxph(Surv(time, status) ~ rx + cluster(litter), rats)
> frailty.model <- coxph(Surv(time, status) ~ rx + frailty(litter), rats)
> marginal.model
Call:
coxph(formula = Surv(time, status) ~ rx + cluster(litter), data = rats)
coef exp(coef) se(coef) robust se z p
rx 0.905 2.47 0.318 0.303 2.99 0.0028
Likelihoo...
2002 Jun 19
2
split plot design with missing plots
...ov "alerted" me that I have done something
wrong. I designed an experiment with all combinations of all levels of each
treatment, but lost a little data (3 out of 192 plots). With the following
data, I run the following model:
> collim[c(1:6,187:192),c(1,3:6,9)]
plot Litter Fert Seed S density
X192.4 192 R 16 C 7 12
X192.3 192 C 16 C 14 26
X192.2 192 C 16 A 8 3
X192.1 192 R 16 A 9 12
X191.4 191 R 32 A 3 0
X191.3 191 C 32 A 10 11
.....
X146.2 146 R 32 C 7...
2012 Sep 14
1
Correlation between random effects in the package coxme
Hello,
Why the correlation between the random effects is negative?
library(coxme)
rats1 <- coxme(Surv(time, status) ~ (1|litter), rats)
random.effects(rats1)[[1]] #one value for each of the 50 litters
print(rats1)
rats2 <- lmekin(time ~ (1|litter), rats)
fixed.effects(rats2)
random.effects(rats2)[[1]] #one value for each of the 50 litters
print(rats2)
cor(random.effects(rats1)[[1]],random.effects(rats2)[[1]])
Thanks...
2005 Mar 09
2
Structural equation models with R
...'reg','folha','solo'))
model.com=matrix(c(
'ridos>dendos', 'a1', NA,
'ridos>reg', 'a2', NA,
'ridos>folha', 'a3', NA,
'ridos>solo', 'a4', NA,
'ridos>raiz', 'a5', NA,
'dendos>litter', 'a6', NA,
'dendos>reg', 'a7', NA,
'litter>reg', 'a8', NA,
'folha>reg', 'a9', NA,
'solo>reg', 'a10', NA,
'raiz>reg', 'a11', NA,
'raiz>solo', 'a12', NA,
'folha>solo...
2003 Apr 29
1
plot with nlme
...ectively, and am wondering if it does not handle unbalanced data (3 out
of 192 missing).
I include below the model and an xyplot that almost does the job. I would
happily send anyone the data if they would be willing to help.
Many Thanks in advance.
Hank
The model:
fm <- lme( log(S,2) ~ Fert*Litter*Seed*Density, data = collimd, random =
~1|block/plot/Seed )
# The following is close, but fits lines within each panel rather than
giving me the fitted values generated by the model.
xyplot( log(S,2) ~ log10(Nper0.5m) | Fert*Seed, data =
collimd, groups=Litter,
scales = list( alte...
2017 Nov 03
0
Pairwise comparison, TukeyHSD, glht, ANCOVA
Hi,
I'm wondering if i can use the function "TukeyHSD" to perform the all pairwise comparisons of a "aov()" model with one factor (e.g., GROUP) and one continuous covariate (e.g., AGE). I did for example:
library(multcomp)
data('litter', package = 'multcomp')
litter.aov <- aov(weight ~ gesttime + dose, data = litter)
TukeyHSD(litter.aov, which = 'dose')
and i get a warning message like this:
Warning message:
In replications(paste("~", xx), data = mf): non-factor ignored: gesttime
Is this process...
2006 Jun 27
3
R on MAC OS X
>
> Dear all,
>
> I have been usig R for some time, but now I have a MAC instead of a
> PC, am I am having problems in reading files...
>
>
> I have tried:
> Data<-read.table("Users/SaraMM/PhD/Analises-LitterBags/Dados-
> Litter.txt",head=T)
>
> but it said:
> Error in file(file, "r") : unable to open connection
> In addition: Warning message:
> cannot open file 'Users/SaraMM/PhD/Analises-LitterBags/Dados-
> Litter.txt', reason 'No such file or directory...
2005 Apr 20
6
Anova - adjusted or sequential sums of squares?
Hi
I am performing an analysis of variance with two factors, each with two
levels. I have differing numbers of observations in each of the four
combinations, but all four combinations *are* present (2 of the factor
combinations have 3 observations, 1 has 4 and 1 has 5)
I have used both anova(aov(...)) and anova(lm(...)) in R and it gave the
same result - as expected. I then plugged this into
2010 Aug 22
2
coxme AIC score and p-value mismatch??
...output for two models constructed with the rats data set.
>library(survival)
>data(rats)
> str(rats)
'data.frame': 150 obs. of 4 variables:
$ time : int 101 104 104 77 89 88 104 96 82 70 ...
$ tumor : int 0 0 0 0 0 1 1 1 0 1 ...
$ trt : int 1 1 1 1 1 1 1 1 1 1 ...
$ litter: int 1 2 3 4 5 6 7 8 9 10 ...
>m1<- coxme(Surv(rats$time, rats$tumor) ~ rats$trt + (1|rats$litter))
>m1
Cox mixed-effects model fit by maximum likelihood
Data: rats
events, n = 40, 150
Iterations= 10 54
NULL Integrated Penalized
Log-likelihood -185.6822 -180...
2011 Jul 08
1
coxme for random effects only model
...countered the following problem where coxme seems to allow
model with only random effect in R 2.11.1 but not in R 2.13.0. Following
is the error message using rat example data. Any comment on this is
appreciated.
In R2.13
> library(coxme)
> rat1 <- coxme(Surv(time, status) ~ rx + (1|litter), rats)
> rat0 <- coxme(Surv(time, status) ~ (1|litter), rats)
Error in coxme.fit(X, Y, strats, offset, init, control, weights =
weights, :
No starting estimate was successful
In R 2.11.1
> library(coxme)
> rat1 <- coxme(Surv(time, status) ~ rx + (1|litter), rats)
&g...
2015 Feb 06
2
Creating users "on - the - fly"
...se forwarding).
I was planning on just having the AuthorizedKeysCommand take the
username, look up the keys from the webservice, and return them. Easy!
The trouble is that the user isn't created on the machine beforehand.
But I actually don't want the user created, b/c I don't want to litter
all these servers with little user directories. Users may be
transient as well - so littering the directories of these machines
with tons of data just causes many other problems (running out of
inodes, disk-space, etc).
Any ideas?
Thanks!
Cary
2015 Feb 06
4
Creating users "on - the - fly"
I guess I didn't want to litter the users table either - it just seems
"wrong" to be actually adding things to the host when it is really so
transient. It feels like it should be LDAP-ish. Just ask the server
for the keys and do a one-off authentication. But I've seen even LDAP
creates the user directories.
I se...
2012 May 21
1
fda modeling
Dear friends - We have 25 rats, 14 of these subjected to partial removal
of kidney tissue, 11 to sham operation, and then followed for 6 weeks.
So far we have data on 26 urine metabolites measured by NMR 7 times
during the observation. I have smoothed the measurements by b.splines in
fda including a roughness penalty, and inspecting the mean curves for
nephrectomized and sham animals indicate
2006 Mar 06
1
P-values from survreg (survival package) using a clusterterm
...ble?)
ICC. Shouldent it be, at least to some extend, comparable to the robust
z-test, for rx : 2*pnorm(-0.239/0.0816)=0.0034 ?
Any help/hints are appreciated.
Steen and R 2.2.1, survival 2.21 on win XP.
library(survival)
data(rats)
marginal.model <- survreg(Surv(time, status) ~ rx + cluster(litter), rats )
summary(marginal.model)
> library(survival)
> data(rats)
> marginal.model <- survreg(Surv(time, status) ~ rx + cluster(litter), rats
)
> summary(marginal.model)
Call:
survreg(formula = Surv(time, status) ~ rx + cluster(litter),
data = rats)
Value Std. Er...
2013 Mar 18
2
Patch to add Unicode filename support for win32 flac
..., i knew i've missed something! :)
> Also, i didn't consider wildcards (i thought shell was supposed to
> handle them...).
I believe that shell does handle wildcards on all Unix variants,
including OSX. Since Windows does not handle them, I suggest that the
main flac code not be littered with code that's not necessary on the
primary platforms. Aren't Windows users accustomed to this feature
being missing anyway?
Brian
2023 Dec 30
1
Help request: Parsing docx files for key words and appending to a spreadsheet
...ning is that the path from getwd() is being appended to the
title of the article, but without the '/' between the end of the path
name (here 'TEST' and the name of the article. In other words,
full_filename is reading "~/TESTNow they want us to charge our electric
cars from litter bins.docx", so logically, this file doesn't exist. To
work, the '/' needs to be inserted to differentiate between the end of
the path name and the start of the article name. I've tried both paste0,
as you suggested, and paste but neither do the trick.
Is this a result of me...
2023 Dec 29
1
Help request: Parsing docx files for key words and appending to a spreadsheet
help(read_docx) says that the function only imports one docx file. In
> order to read multiple files, use a for loop or the lapply function.
>
I told you people will suggest better ways to loop!!
>
> docx_summary(read_docx("Now they want us to charge our electric cars
> from litter bins.docx")) should work.
>
Ivan thanks for spotting my fail! Since the OP is new to all this I'm going
to suggest a little tweak to this code which we can then build into a for
loop:
filepath <- getwd() #you will want to change this later. You are doing
something with tcl to pick...