Displaying 4 results from an estimated 4 matches for "totvar".
2008 Aug 15
2
Design-consistent variance estimate
...data = mm)
svymean(~score, gg, deff='replace', na.rm=TRUE)
### My code which replicates the formulae in the LaTeX code below
## Cluster totals
xx <- with(mm, tapply(score, group, sum, na.rm=TRUE))
## Mean of the total
ss <- mean(xx, na.rm=T)
## get total variance
k <- length(xx)
totvar <- sum((xx-ss)^2) * k/(k-1)
## The SE is then
N <- nrow(mm)
sqrt(totvar/N^2)
One additional thing to point out is this:
## sqrt of variance of the total is:
> svytotal(~score, gg)
total SE
score -1.7923 21.139
## sqrt of variance of total from my code
> sqrt(totvar)
[1] 2...
2006 Nov 24
2
low-variance warning in lmer
...ht place ...)
thanks
Ben Bolker
self-contained but unnecessarily complicated simulation
code/demonstration:
---------------
library(lme4)
library(lattice)
simfun <- function(reefeff,ntreat=2,nreef=12,
nreefpertreat=3,
t.eff=10,
totvar=25,seed=NA) {
if (!is.na(seed)) set.seed(seed)
ntot = nreef*nreefpertreat
npertreat=ntot/ntreat
reef = gl(nreef,nreefpertreat)
treat = gl(ntreat,npertreat)
r.sd = sqrt(totvar*reefeff)
e.sd = sqrt(totvar*(1-reefeff))
y.det = ifelse(treat==1,0,t.eff)
r.vals = rnorm(nreef,sd=r.sd)...
2005 May 23
1
Can't reproduce clusplot princomp results.
Dear R folk:
Perhaps I'm just dense today, but I am having trouble reproducing the
principal components plotted and summarized by clusplot. Here is a brief
example using the pluton dataset. clusplot reports that the first two
principal components explain 99.7% of the variability. But this is not what
princomp is reporting. I would greatly appreciate any advice.
With best regards,
-- Tom
2004 Sep 02
3
confidence intervals
Dear R users;
Im working with lme and Id like to have an idea of how
can I get CI for the predictions made with the model.
Im not a stats guy but, if Im not wrong, the CIs
should be different if Im predicting a new data point
or a new group. Ive been searching through the web and
in help-lists with no luck. I know this topic had been
asked before but without replies. Can anyone give an
idea of