Displaying 20 results from an estimated 400 matches similar to: "define F-ratio computations with aov"
2009 Mar 06
3
PCA and categorical data
Hi all,
I' m trying to figure out if it is appropriate to do a PCA having only categorical data (not ordinal). I have only find the following quote:
One method to find such relationships is to select appropriate variables and
to view the data using a method like Principle Components Analysis (PCA) [4].
This approach gives us a clear picture of the data using KL-plot of the PCA.
However, the
2005 Jan 27
3
Domain admins not getting local admin rights
Hi there,
I switched servers yesterday.
The old server was running 2.2.7a-1 on RedHat 8.0.
The new server is 3.0.8-0.pre1.3 on Fedora Core 3.
I did the migration by copying the following:
/etc/passwd
/etc/group
/etc/shadow
/etc/samba/*
I then copied /home and fixed all the permissions on stuff.
I then started up samba on the new server, and unplugged the old one.
Most everything went
2009 Aug 20
1
nested, repeated measure lme
Dear all,
Suppose I have a nested, repeated measure lme model. Which of the following formulae is correct?
(assuming data are sampled from several plots in an agricultural experiment)
(1) y~explanatory.variables,random=~time|block/plot/subplot/individual
(2) y~explanatory.variables,random=~time|unique.ID.of.every.individual
I have read that (2) is the only approach that works. But how could I
2011 Oct 05
2
subplot strange behavoir
Hello,
Below is some example code that should reproduce an error I'm encountering
while trying to create a tiff plot with two subplots. If I run just the
following bit of code through the R GUI the result is what I'd like to have
appear in the saved tiff image:
x<-seq(0:20)
y<-c(1,1,2,2,3,4,5,4,3,6,7,1,1,2,2,3,4,5,4,3,6)
plot(x,y,type="l",las=1,ylim=c(0,12))
2005 Jul 13
1
unexpected par('pin') behaviour
hi everybody,
I noticed the following: in one of my scripts 'layout' is used to
generate a (approx. square) grid of variable dimensions (depending on
no. of input files). if the no. of subplots (grid cells) becomes
moderately large (say > 9) I use a construct like
###layout grid computation and set up occurs here###
...
opar <- par(no.readonly = T);
2008 May 15
2
mixed effects models with nested factors
Hi everybody,
I am trying to fit a model with the lmer function for mixed effects. I have an experimental design consisting of 5 field plots. Each plot is divided in 12 subplots where the influence of three factors on the growing of tree seedlings is tested: (1) seed (1 = presence; 0 = absence); (2) seedling species (oak holm vs. pine); (3) treatment (three different treatments). In each of
2010 Sep 16
1
Help with graphic margin
Hi everyone.
I would like to make a graphic with 2 subplots (lets say A and B). For
instance, I use :
par(mfcol = c(2,1));
The 2 subplots use the same X axis. So I provide no tics labels and no xlab
for the top plot. I would like the second plot to be right bellow the first
one (small margin).
So my question is how I can keep a small gap between the 2 plots while
having enough space under
2005 Sep 19
1
minimal hedge variance ratio
Hi all
i have two data sets, spot and futures cash market prices. to estimate
the minimum variance hedge ratio, i first had a glance on the
correlation coefficient of relative price change (ln(St / St-1).
surprizingly the value is just 0.2 compared to actual price
correlation of 0.9. (i did regress the spot change on future change,
co-effi is 0.3, and R2 is only 0.025
a) in such scenario can
2011 Nov 03
0
anova or liklihood ratio test from biglm output
(Sorry if this is a repost, I got a bounce reply from the r-help server)
Hi,
I’m using the biglm() function to create some linear models for a very
large data set than lm() can’t fit due to memory issues (the problem is
with the number of interactions, I can fit the main effects model)
I need to determine if the 2-way interactions are necessary or not. Ideally
I’d like to use anova() to
2007 Aug 07
0
Lo and MacKinlay variance ratio test (Lo.Mac)
Hi all,
I am trying to calculate the variance ratio of a time series under
heteroskedasticity.
So I know that the variance ratio should be calculated as a weighted average
of autocorrelations.
But I don't find the same results when I calculate the variance ratio
manually and when I compute the M2 (M2 for heteroskedasticity) variance
ratio using Lo.Mac function in R.
Anybody knows what
2011 Oct 05
1
variance ratio test
Hello,
I am looking for a code in R for the variance ratio test statistic (the
Lo and Mackinlay version or any other versions).
Does anybody have such a code they can share or know a library in which
I can find this function?
Basically I have a number of time series which I need to check for
persistence. One other test I can use is the runs test in the tseries
package.
Any help will be greatly
2011 Sep 17
0
Fw: likelihood ratio test
Ms.Karunambigai M
PhD Scholar
Dept. of Biostatistics
NIMHANS
Bangalore
India
----- Forwarded Message ----
From: karuna m <m_karuna2002@yahoo.com>
To: R-help@r-project.org
Sent: Thu, 26 May, 2011 10:55:02 AM
Subject: likelihood ratio test
Dear R-help,
Can anybody tell me which R package has Lo-Mendell Rubin LR test and Bootstrap
LR test to compare the model fit between k class and k+1
2010 Feb 16
1
survival - ratio likelihood for ridge coxph()
It seems to me that R returns the unpenalized log-likelihood for the ratio likelihood test when ridge regression Cox proportional model is implemented. Is this as expected?
In the example below, if I am not mistaken, fit$loglik[2] is unpenalized log-likelihood for the final estimates of coefficients. I would expect to get the penalized log-likelihood. I would like to check if this is as expected.
2010 Apr 30
2
Likelihood ratio based confidence intervals for logistic regression
I'm applying logistic regression to a moderate sized data set for which I
believe Wald based confidence intervals on B coefficients are too
conservative. Some of the literature recommends using confidence intervals
based on the likelihood ratio in such cases, but I'm having difficulty
locating a package that can do these. Any help would be immensely
appreciated.
Best,
Jeff Hanna
--
2003 Mar 15
1
plots to metafile and x/y ratio
Dear all,
I have a problem which I'm not sure if it is due to my machine or if I'm
doing something wrong.
I'm ploting a little map using plot(val, type="l", asp=1) where val is
the object with the latitude/longitude data.
In the screen the figure is perfect, and I can copy to the clipboard and
paste it to other places. I can also saved using png() or jpeg(),
althoug
2010 Jul 30
1
COXPH: how to get the score test and likelihood ratio test for a specific variable in a multivariate Coxph ?
Hello,
I would like to get the likelihood ratio and score tests for specific variables
in a multivariate coxph model. The default is Wald, so the tests for each
separate variable is based on Wald's test. I have the other tests for the full
model but I don't know how to get them for each variable.
Any idea?
David Biau.
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2004 Aug 19
1
sample selection problem, inverse mills ratio (Heckman, Lewbel, ...)
-----Ursprüngliche Nachricht-----
Von: Wildi Marc, wia
Gesendet: Mittwoch, 18. August 2004 10:11
An: r-help@lists.R-project.org
Betreff:
Hi
Does anybody know from an R-package devoted to sample selection problems (Heckman's lambda, Lewbel, ...)?
Thanks and best regards
Marc Wildi
[[alternative HTML version deleted]]
2000 Sep 11
0
plots: aspect ratio
After playing around I got everything to work. One problem was
with the large pointsizes. I switched to small pointsizes and shrank the
plot region. This shrank the gaps and tick lengths down to reasonable
values.
As for aspect ratio, I think the pty="s" did finally kick in somehow. In
the old days this was not required; the dev.print width=, height= took
care of that.
Cheers,
Bill
2013 Mar 14
0
Fw: showing ratio in ggplot bar plot with facets
Dear R help members,
I have constructed a bar plot using ggplot, where I am showing the number of particles in 10m depth bins (from 0-150m) by release area (3 different ones) and Model (also 3 different ones). My problem is that for each release area a different number of particles was released (say 35, 45 and 56). I now need to be able to show the number of particles in each depth bin
2011 Jan 26
2
crash when using hazard.ratio.plot from rms package
Dear all,
I always encounter a crash when running hazard.ratio.plot from rms package with my predictor as a factor.
It works fine when the predictor is a continous score.
Anyone encounters this too? Is this a bug or something?
Thanks,
Lilian
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