Displaying 20 results from an estimated 9000 matches similar to: "compare quality of clustering methods?"
2010 Apr 21
1
Can I compare two clusters without using their distance-matrix (dist()) ?
Hello all,
I would like to compare the similarity of two cluster solutions using a
validation criteria (such as Hubert's gamma coefficient, the Dunn index the
corrected rand index and so on)
I see (from here:http://www.statmethods.net/advstats/cluster.html) that
the function cluster.stats() in the fpc package provides a mechanism
for comparing 2 cluster solutions - *BUT* - it requires me to
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
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
2009 Oct 08
5
histogram
Hi all,
I have a question about hist()
1)
> t1 <- hist(c(1,2,3,4,5))
> t1
$breaks
[1] 1 2 3 4 5
$counts
[1] 2 1 1 1
why is there 2 counts for 1? And should the counts be '1 1 1 1 1' ?
Is there any other function to count frequency of discrete data?
Thanks.
-k
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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 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
2010 Jul 08
1
How can i draw a graph with high and low data points
Hi,
This is my first time so bear with me if I do anything silly. I'll learn!
I'm a relatively new user of R as well so will appreciate any help.
I have a data set in the form
Trial.Group MeanHeart Rate Upper confidence level Lower confidence level
333subj: 0-5 M 80 60 120etcetc
I want to plot a graph that has Trial.Group on the x axis(names, not just an
2009 Dec 10
1
problem with data processing in R
Hi,
I'm stuck with parsing data into R for heatmap representation.
The data looks like:
1 id1 x1 x2 x3 .... x20
2 id1 x1 x2 x3 .... x20
3 id1 x1 x2 x3 .... x20
4 id1 x1 x2 x3 .... x20
.........
348 id2 x1 x2 x3 .... x20
349 id2 x1 x2 x3 .... x20
350 id2 x1 x2 x3 .... x20
351 id2 x1 x2 x3 .... x20
.........
The data is sorted for the IDs (id1,id2 .....id40) and I like to
2012 May 12
7
[Patches] mesa/nv30: Diverse set of patches that improve NV3x render quality V2
A reworked version of 3 out of 4 patches mentioned earlier.
[1/4]: Fixes nearly all piglit vertprog testcases, due to now being able to pass the results on to the fragment shader. V2: rename samplers to texcoords.
[2/4]: Fixes shader compiler assertion errors, as some source registers do not exist for certain operations. Fixes several piglit tests when mesa is compiled with --enable-debug
[3/4]:
2008 Mar 05
2
Principle component analysis
Thanks to Mr.Liviu Androvic and Mr.Richard Rowe helped me in PCA.
Because I have just learn R language in a few day so I have many problem.
1) I don't know why PCA rotation function not run although I try many times.
Would you please hepl me and explain how to read the PCA map (both of
rotated and unrotated) in a concrete example.
2) Where I can find document relate: Plan S(A), S(A*B),
2010 Jan 05
1
bootstrapping a matrix and calculating Pearson's correlation coefficient
Hi All,
I have got matrix 'data' of dimension 22000x600. I want to make 50
independent samples of dimension 22000x300 from the original matrix 'data'.
And then want to calculate pearsons CC for each of the obtained 50 matrices.
It seems it is possible to do this using 'boot' function from library boot
but I am not able to figure out how? I am really stuck. Please help!
2010 Apr 24
1
Multiple Correlation coefficient (spearman, Kenall)
Hi,
I'm currently trying to find/define a relationship between one dependent and
several independant variables.
The problem is that i cannot use the normal multiple regression/correlation
in Spss because the data is not normal distributed.
i calculated the spearman roh and Kendalls tau Correlation and also some
partial correlations in R.
Now i wanna find out the the multiple correlation
2008 Mar 03
2
Problem with PCA
I have an exercise. With 3 kinds of yohourt a,b,c. There are 25
participatients estimate 3 norms: taste (va,vb,vc), structure (ca,cb,cc) and
price (ga,gb,gc) and give the mark from 1 to 5. I don't know how to PCA this
data. Please help me!
I attached the data file follow:
Va Vb Vc Ca Cb Cc Ga Gb Gc
4 2 4 5 5 5 4 4 2
2 2 4 3 2 5 4 5 1
2 2 1 2 3 3 3 1 4
1 1 2 2 3 3 4 3 2
3 4 4 4 3 1 2 1 2
1 1 1
2010 Mar 27
7
large dataset
Hi I have a question,
as im not able to import a csv file which contains a big dataset(100.000 records) someone knows how many records R can handle without giving problems?
What im facing when i try to import the file is that R generates more than 100.000 records and is very slow...
thanks a lot!!!
2009 Oct 09
2
Creating a Clustered-Stacked Column Chart
Hi all,
In R, is there some functions or ways to create a Clustered-Stacked
Column Chart as the example in the following page
http://peltiertech.com/Excel/ChartsHowTo/ClusterStack.html?
I have browsed the R Graph Gallery (http://addictedtor.free.fr/graphiques/)
and searched the R site, and didnot find an appropriate method to do it.
Anybody has met this problem before?
Thanks a lot.
2012 May 09
4
[Patches]mesa/nv30: Diverse set of patches that improve NV3x render quality
For all these patches I'd say: testers are welcome. The first three patches seem good enough to push as we speak IMHO (so if you agree, go ahead!), whereas for the fourth I don't know if this is the desired way to fix. The result of these four patches is that NV34 gives a nearly-correct desktop experience, where only some fading animations appear broken. It's quite useable now!
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