Displaying 20 results from an estimated 4000 matches similar to: "Help with ANOVA"
2007 Nov 22
3
anova planned comparisons/contrasts
Hi,
I'm trying to figure out how anova works in R by translating the
examples in Sokal And Rohlf's (1995 3rd edition) Biometry. I've hit a
snag with planned comparisons, their box 9.4 and section 9.6. It's a
basic anova design:
treatment <- factor(rep(c("control", "glucose", "fructose",
"gluc+fruct",
2003 Jun 30
1
Fw: VPN setup problem - proxy arp I think
Hi all,
I read the setup at http://www.blackh0le.net/articles/vpn-dun-howto.html to setup my VPN.
However, I'm having a problem which I think is proxy-ARP not working. I like to ask you to see if you know what's going on. When I ping 10.77.1.1 from windows XP machine the packets get to the 10.77.1.1 machine, but they don't have a return path to get back. When I do ping the windows
2010 Jun 16
4
Is there a non-parametric repeated-measures Anova in R ?
Hello Prof. Harrell and dear R-help mailing list,
I wish to perform a non-parametric repeated measures anova.
If what I read online is true, this could be achieved using a mixed Ordinal
Regression model (a.k.a: Proportional Odds Model).
I found two packages that seems relevant, but couldn't find any vignette on
the subject:
http://cran.r-project.org/web/packages/repolr/
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
2010 Mar 07
1
Is there an equivalence of lm's “anova” for an rpart object ?
Simple example:
# Classification Tree with rpart
library(rpart)
# grow tree
fit <- rpart(Kyphosis ~ Age + Number + Start,
method="class", data=kyphosis)
Now I would like to know how can I measure the "importance" of each of my
three explanatory variables (Age, Number, Start) in the model?
If this was a regression model, I could have looked at p values from the
2010 May 06
1
How to solve: Error with Anova {car} due to "deficient rank" ?
Hello all,
I am getting the following error:
Error in linear.hypothesis.mlm(mod, hyp.matrix.1, SSPE = SSPE, V = V, :
The error SSP matrix is apparently of deficient rank = 7 < 11
After running:
mod.ok <- lm(as.matrix(dat[,-1]) ~ DC, data=dat)
(av.ok <- Anova(mod.ok, idata=idata, idesign=~week))
Although if I jitter the data in "dat", the function seems to work.
What
2009 Nov 18
2
Importing tRNA data into R ?
Hello dear R help group,
I would like to download the tRNA data on:
http://gtrnadb.ucsc.edu/download.html
And then import it into R.
Can anyone direct me as to how to do so?
Thanks,
Tal
----------------------------------------------
My contact information:
Tal Galili
E-mail: Tal.Galili@gmail.com
Phone number: 972-52-7275845
FaceBook: Tal Galili
My Blogs:
http://www.talgalili.com (Web and
2009 Nov 20
6
How to: highlight R syntax on webpages ?
My question if in the Subject, but if to extend: I am specifically curious
about WordPress blogs. But any solution will give me a lead.
Thanks,
Tal
----------------------------------------------
Contact me: Tal.Galili@gmail.com | 972-52-7275845
Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) |
www.r-statistics.com/ (English)
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2011 Oct 06
1
anova.rq {quantreg) - Why do different level of nesting changes the P values?!
Hello dear R help members.
I am trying to understand the anova.rq, and I am finding something which I
can not explain (is it a bug?!):
The example is for when we have 3 nested models. I run the anova once on
the two models, and again on the three models. I expect that the p.value
for the comparison of model 1 and model 2 would remain the same, whether or
not I add a third model to be compared
2010 Jan 01
4
How to use read.table with Hebrew column names ?
Hello dear R help group,
I am trying to read a .txt file, with Hebrew column names, while keeping the
column names looking well in R - but without success.
I uploaded an example file to:
http://www.talgalili.com/files/aa.txt
And am trying the command:
read.table("http://www.talgalili.com/files/aa.txt", header = T, sep = "\t")
This returns me with:
X.....ª X...ª......
2010 May 22
2
Capturing R console output into a file (sink+savehistory ??)
After reading more, I understand I didn't formulate my last question
correctly, so please allow me to rephrase:
What I am looking for is a way to save the R console session output.
That is, a command that would combine the results of using:
?sink # And
?savehistory
My motivation for this is that doing it will allow someone who is a blind
user of R to be able to easily export his results to
2010 May 08
3
Count cases in a list
Hi everybody, I would like to count how many times names in list L,
nombreL, apear in list C, nombreC.
Can I improve the next program?
cuenta <- 0
topL <- length(nombreL)
topC <- length(nombreC)
for (i in 1:topL) {
for (j in 1:topC) {
k <-
grep(noquote(nombreL[i]),nombreC[j])
2010 Jul 02
3
Combining several plots besides a dendrogram?
Hello all,
I would like to recreate the plot shown here (from a useR 2009
presentation):
http://www.agrocampus-ouest.fr/math/useR-2009/abstracts/pdf/Hocking.pdf
I downloaded the code for that image, and discovered that it relies on
external web services, and also having PERL installed on the computer.
I believe this could be done "locally" using the "seqLogo"
2009 Oct 14
2
Scatter plot using icons (from a gif) instaed of points - is it possible ?
Hello dear R-help group.
I wish to plot a scatter plot using icons (or images) instead of points.
Is it possible? and how so?
Thanks,
Tal
----------------------------------------------
My contact information:
Tal Galili
E-mail: Tal.Galili@gmail.com
Phone number: 972-52-7275845
FaceBook: Tal Galili
My Blogs:
http://www.talgalili.com (Web and general, Hebrew)
http://www.biostatistics.co.il
2011 Dec 29
3
Is it possible to "right align" text in R graphics?
Hello all,
The following line of code includes a right-to-left language text, yet the
R graphics engine displays it from left to right. One problem this causes
is when there are parenthesis in the test, here is a basic example?
plot(1:10, main = "שלום (טקסט)")
Is there a way to make sure the text is displayed from right to left?
Many thanks for any suggestions,
Tal
2011 Apr 18
2
Windows 7, update.packages problem: "unable to move temporary installation"?
Hello all,
I am using R 2.13.0 with windows 7, after giving my user full privileges to
the R folder (as described
here<http://www.r-statistics.com/2011/04/how-to-upgrade-r-on-windows-7/>
).
This allows me to install new packages just fine.
However, when using update.packages(), to update existing packages, I keep
getting the following error (for example, when updating the MASS package):
2010 Nov 09
3
Is there a way to have 'comment' keep a list?
Hello all,
I recently discovered the "comment" command.
I see it can only hold a vector of characters.
Is there a way (or an alternative), to make it possible to have it keep a
list?
(for example, to keep different pieces of information like date of creation,
information of each variable and so on)
The closest solution I can think of is using 'names' on the vector, like
this:
2010 Jan 21
2
"stack imbalance in ..." when loading a workspace
Hi all,
I just failed in loading a saved wordspace (13MB of size), and received
these errors:
Warning: stack imbalance in 'missing', 52 then 51
Warning: stack imbalance in 'if', 50 then 53
Warning: stack imbalance in 'as.environment', 57 then 59
Warning: stack imbalance in 'ls', 54 then 53
Warning: stack imbalance in '.Internal', 54 then 53
Warning: stack
2010 Nov 25
3
Is there an implementation for "URL Encoding" (/format) in R?
Hello all,
I would like some R function that can translate a string to a "URL encoding"
(see here: http://www.w3schools.com/tags/ref_urlencode.asp)
Is it implemented? (I wasn't able to find any reference to it)
Thanks,
Tal
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Contact me: Tal.Galili@gmail.com | 972-52-7275845
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2010 Apr 26
2
Using optim function for logistic model simulation
Hello!
I'm a college undergrad desperately trying to finish up my thesis. I
have a dataset on the distribution of a grassland bird from the
Breeding Bird Survey. I have a very straightforward and simple version
of the logistic growth model to describe changes in this bird's
abundance over time. The variables are the natural birth rate,
mortality, and carrying capacity. The equation itself