Displaying 20 results from an estimated 7000 matches similar to: "Can I compare two clusters without using their distance-matrix (dist()) ?"
2010 Oct 30
1
compare quality of clustering methods?
Hi,
Suppose I want to compare the results of two clustering methods, what
is the best way to do it? Thanks
Regards,
-k
2012 Mar 04
1
rpart package, text function, and round of class counts
I run the following code:
library(rpart)
data(kyphosis)
fit <- rpart(Kyphosis ~ ., data=kyphosis)
plot(fit)
text(fit, use.n=TRUE)
The text labels represent the count of each class at the leaf node.
Unfortunately, the numbers are rounded and in scientific notation rather
than the exact number of examples sorted by that node in each class.
The plot is supposed to look like
2010 May 05
2
OLS Regression diagnostic measures check list - what to consider?
Hello dear R help list,
I wish to compile a check-list for diagnostic measures for OLS regression.
My question:
Can you offer more (or newer) tests/measures for the validity of a linear
model then what is given here:
http://www.statmethods.net/stats/rdiagnostics.html
This resource gives a list of measures to test for:
OUTLIERS, INFLUENTIAL OBSERVATIONS, NON-NORMALITY, NON-CONSTANT ERROR
2008 Mar 06
2
Principle component analysis function
Dear All,
In a package, I want to use PCA function. The structure I used follow this
page: http://www.statmethods.net/advstats/factor.html.
fit<-principle(mydata, nfactors=9, rotation=TRUE)
or:
result<-PCA(mydata)
But I don't known why R language in my computer noticed: "not found
principle", "not found PCA".
I download and installed
2010 Jul 08
1
Histogram Principal component analysis in R
Hi,
I am trying to do a Principal component analysis on histogram data.
Basically, I have a group of subjects and for each of them, I have a column
of bin-counts (vis-a-vis intervals) and a corresponding column of
frequencies (or normalized frequencies). The bin counts are the same for all
the subjects. I also have a group-averaged histogram (with the same bin
counts and a column of frequencies)
2010 Jul 27
1
as.dendrogram for DICE coefficient.
Hi R,
I was using 'as.dendrogram' with the DIST coefficient, where the smaller
values of the DIST coefficient, say that the objects are closer to each
other, while the larger values of the coefficient say that the objects
are far from each other.
But now, I have my coefficient as the DICE coefficient(in some sense
similar to correlation coefficient), where the larger coefficient
2010 Oct 22
1
question about decision trees
Hi, I have seen that R has a implementation of decision trees; however,
after I have the tree with the classification:
R Quinlan's trivial example of the "golf" decision tree.
Outlook Temperature Humidity Windy PlayDontPlay 1 sunny 85 85 false
DontPlay
2 sunny 80 90 true DontPlay
3 overcast 83 78 false Play
4 rain 70 96 false Play
...
What's next? I mean, what is this
2010 May 03
1
rpart, cross-validation errors question
I ran this code (several times) from the Quick-R web page (
http://www.statmethods.net/advstats/cart.html) but my cross-validation
errors increase instead of decrease (same thing happens with an unrelated
data set).
Why does this happen?
Am I doing something wrong?
# Classification Tree with rpart
library(rpart)
# grow tree
fit <- rpart(Kyphosis ~ Age + Number + Start,
2013 Jul 02
1
Recursive partitioning on censored data
I am interested in applying a "classification tree" analysis where the
response variable is a censored variable (survival data).
I've discovered the package 'party' through this page:
http://www.statmethods.net/advstats/cart.html. However, as my sample is not
very big I would like to apply 'bootstrap' and use 'random forests', but
with my censored response
2011 Sep 08
1
"rpart" or "tree" function issue
I am trying to create a classification tree using either tree or rpart
functions but when it comes to plotting the results the formatting I get is
different than what I see in all the tutorials (like
http://www.youtube.com/watch?v=9XNhqO1bu0A or
http://www.youtube.com/watch?v=m3mLNpeke0I&feature=related or
http://www.statmethods.net/advstats/cart.html "tree for kyphosis"). I am
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
2010 May 03
1
Comparing the correlations coefficient of two (very) dependent samples
Hello all,
I believe this can be done using bootstrap, but I am wondering if there is
some other way that might be used to tackle this.
#Let's say I have two pairs of samples:
set.seed(100)
s1 <- rnorm(100)
s2 <- s1 + rnorm(100)
x1 <- s1[1:99]
y1 <- s2[1:99]
x2 <- x1
y2 <- s2[2:100]
#And both yield the following two correlations:
cor(x1,y1) # 0.7568969 (cor1)
cor(x2,y2)
2010 Dec 07
1
Encoding problem - I fails to read Hebrew text from online
Hello all,
# I am trying to read the text in this URL:
u <-
http://google.com/complete/search?output=toolbar&q=%d7%a9%d7%9c%d7%95%d7%9d
# By using this command:
readLines(u)
And no matter what variation I tried, I keep getting this output:
[1] "<?xml version=\"1.0\"?><toplevel><CompleteSuggestion><suggestion
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
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)
[[alternative HTML version deleted]]
2012 Jan 30
1
Getting htmlParse to work with Hebrew? (on windows)
Hello dear R-help mailing list.
I wish to be able to have htmlParse work well with Hebrew, but it keeps to
scramble the Hebrew text in pages I feed into it.
For example:
# why can't I parse the Hebrew correctly?
library(RCurl)
library(XML)
u = "http://humus101.com/?p=2737"
a = getURL(u)
a # Here - the hebrew is fine.
a2 <- htmlParse(a)
a2 # Here it is a mess...
None of
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 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
----------------Contact
Details:-------------------------------------------------------
Contact me: Tal.Galili@gmail.com | 972-52-7275845
Read me:
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):
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