Displaying 20 results from an estimated 110 matches similar to: "two way ANOVA with unequal sample sizes"
2005 Mar 08
1
coefficient of partial determination...partial r square [ redux]
If I'm not mistaken, partial R-squared is the R^2 of the quantities plotted
in a partial residual plot, so you can base the computation on that. Prof.
Fox's `car' package on CRAN has a function for creating those plots, but you
need to figure out the way to extract the quantities being plotted.
[In any case, the basic tools for doing such computations are all in R, and
it
2006 Jun 10
1
Maximum likelihood estimation of Regression parameters
Hi,
I want to use Maximum likelihood to estimate the parameters from my regression line.
I have purchased the book "Applied linear statistical models" from Neter, Kutner, nachtsheim & Wasserman, and in one of the first chapters, they use maximum likelihood to estimate the parameters.
Now I want to tried it for my self, but couldn't find the right function.
In the book, they give
2009 Nov 18
1
How to choose appropriate linear model? (ANOVA)
I'm wondering how to choose an appropriate linear model for a given
problem. I have been reading Applied Linear Regression Models by John
Neter, Michael H Kutner, William Wasserman and Christopher J.
Nachtsheim. I'm still not clear how to choose an appropriate linear
model.
For multi-factor ANOVA, shall I start with all the interaction terms
and do an F-test to see with interaction terms
2005 Oct 16
1
measurement error model - "simple" linear regression
Dear friends, I found the thread on this subject this summer but
wonder whether it has been taken any further. I have an important
medical problem where X is computed from a three independent and
complicated measurements (exchangeable sodium and potassium and total
body water - i.e. X = (Nae+Ke)/TBW ) and Y is serum sodium
concentration (all data in Edelman, JCI 1958). I have the individual
2005 Jul 20
1
predict.lm - standard error of predicted means?
Simple question.
For a simple linear regression, I obtained the "standard error of
predicted means", for both a confidence and prediction interval:
x<-1:15
y<-x + rnorm(n=15)
model<-lm(y~x)
predict.lm(model,newdata=data.frame(x=c(10,20)),se.fit=T,interval="confidence")$se.fit
1 2
0.2708064 0.7254615
2006 Nov 17
2
effects in ANCOVA
Dear R users,
I am trying to fit the following ANCOVA model in R2.4.0
Y_ij=mu+alpha_i+beta*(X_ij-X..)+epsilon_ij
Particularly I am interested in obtaining estimates for mu, and the effects
alpha_i
I have this data (from the book Applied Linear Statistical Models by Neter
et al (1996), page 1020)
y<-c(38,43,24,39,38,32,36,38,31,45,27,21,33,34,28)
2007 Jun 05
1
logit model interpretation
Hello everyone
I appologize for my lack of experience in statistical methods. I am an R
user begginer and I am running a logit model using "zelig" and "pcse"
packages. I will go to the point and is that Im having problems with
interpreting the results of my models.. It is really simple (I guess for the
most advanced scholars) however I really dont understand how to interpret
2000 Dec 13
2
randomized block design and two-way factorial design
I am still a little unclear in the difference between
randomized block design and two-way factorial design
after consulting a few books, including John Rice
Mathematical Statistics and Data Analysis.
Both put observations in cells corresponding to two factors
of many levels. Both use the same computer program to analyze
data.
It seems that randomized block design can have only one observation
2000 Feb 23
2
Files unavailable on CRAN
I've been trying to download from CRAN the floppy versions of the R source
files:
R-release-1.tar.gz, R-release-2.tar.gz
I tried the servers in Seattle, Madison, and the Vienna
Technical University. In each case, the file(s) were unavailable.
Anne
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Anne E. York
National Marine Mammal Laboratory
Seattle WA 98115-0070 USA
e-mail: anne.york at noaa.gov
2007 Mar 01
2
Another newbie book recommandation question
I hope this question is sufficiently different from the other requests
for book recommendations that it's not repetitious. If not, I apologize
in advance.
I'm curious what standard reference books working statisticians, or
biostatisticians, have within easy reach of their desk. I'm a computer
systems administrator, and have a two-foot bookshelf directory under my
monitor that contains
2011 Mar 29
1
Simple AR(2)
Hi there, we are beginners in R and we are trying to fit the following time
series using ar(2):
> x <- c(1.89, 2.46, 3.23, 3.95, 4.56, 5.07, 5.62, 6.16, 6.26, 6.56, 6.98,
> 7.36, 7.53, 7.84, 8.09)
The reason of choosing the present time series is that the we have
previously calculated analitically the autoregressive coefficients using
the direct inversion method as 1.1, 0.765, 0.1173.
2009 Jan 23
5
Stat textbook recommendations?
Hello,
I'm looking for a textbook that can explain some of the math behind
the intro-to-intermediate stuff like ANOVA, multiple regression, non-
parametric tests, etc.
A little background: I took an intro stats course last year and
would like to further my education. Being as that was the highest
(and only) stats class the local community college offers, it looks
like I'm on
2009 Aug 13
4
lm coefficients output confusing
Hi all,
I have an issue with the lm() function regarding the listing of the
coefficients. My data are below, showing a list of hours (HR) relating to
the time spent resting (R) by an individual animal. Simply i want to run a
lm() to run in an anova() to see if there is a significant difference in
resting between hours.
HR R
1 2 0.6666667
2 2 0.4666667
3 2 0.8000000
4 2
2003 Apr 09
1
[OFF] Nested or not nested, this is the question.
Hi,
sorry by this off.
I'm still try to understand nested design.
I have the follow example (fiction):
I have 12 plots in 4 sizes in 3 replicates (4*3 = 12)
In each plot I put 2 species (A and B) to reproduce.
After a period I make samples in each board and count the number of
individuals total (tot) and individuals A and B (nsp). Others individuals
excepts A and B are in total of
2007 Aug 07
1
bayesm - question about 'rscaleUsage function'
Hi all,
I have managed to get the r-scale usage algorithm to work, but I need to obtain the final results from this. As I understand it, this code is designed to generate a matrix after processing and store it somewhere?????
Here is the code.....
I get this part of the code, it all makes sense.
##
if(nchar(Sys.getenv("LONG_TEST")) != 0) {R=1000} else {R=5}
{
data(customerSat)
2003 Dec 02
1
question regarding variance components
I am using a two-factor ANOVA model with random factor effects including
the interaction, i.e. the factors are crossed. I would like to be able to
generate all four variance components along with approximate confidence
intervals using the NLME package. However, I do not know how to specify
the random option because of two problems. First, I do not know how to
enter the interaction term into the
2011 Aug 09
1
need your consult
Dear Sir/Madam
Hi. I am a general paediatrician, and I have read *some* chapters of the
following books(1-3). I think SPSS lacks some features that may be important
in data analysis (for example: interval of correlation coefficient in
bivariate normal distribution, PRESS, and MSPR in cross-validation). I am
thinking about changing SPSS to R:
1. SPSS is very expensive for me to update.
2002 Aug 14
0
: use of Error() for repeated measures with more than 2 factors
I have been trying to analyse an unreplicated repeated measures 2-level
factorial design with 11 factors using aov() with Error(), similar to
that described in "Notes on the use of R for psychology experiments and
questionnaires" by Jonathan Baron and Yuelin Li (see the example of Hay's)
I have found that there seems to be a limit, in the number of factors in
Error() . For
2000 Feb 23
0
Lack of Fit test
> From: "Alan T. Arnholt" <arnholt at math.appstate.edu>
> To: Bill Venables <William.Venables at cmis.CSIRO.AU>
> Cc: r-help at stat.math.ethz.ch, arnholt at math.appstate.edu
> Subject: Re: [R] Lack of Fit test
> Date: Wed, 23 Feb 2000 09:40:21 -0500 (EST)
> X-Authentication: none
>
>
> I guess my question was not adequately stated when I sent
2002 Aug 19
0
: Bug in Error() and the use of Error() for repeated measures with more than 2 fa ctors
I forgot to mention that this analysis was carried out using the Windows
version .
Perhaps this problem is windows specific.
Peter
Peter Ho wrote:
> Prof. Ripley,
>
> I am sending this to you again, as the first one was undelivered.
>
>
> Peter
>
> ripley at stats.ox.ac.uk wrote:
>
>
>>> There is no intended limit, but there was a bug fix in 1.5.0. If