Displaying 20 results from an estimated 2000 matches similar to: "Principle component analysis function"
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),
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
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 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 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 Jan 28
3
how to get coefficient and scores of Principal component analysis in R?
Dear All,
It might be a simple question. But I could not find the answer from function “prcomp” or “princomp”. Does anyone know what are the codes to get coefficient and scores of Principal component analysis in R?
Your reply will be appreciated!
Best
Zunqiu
[[alternative HTML version deleted]]
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
2013 Aug 29
1
Resumen de R-help-es, Vol 54, Envío 22
Hola! No he podido consultar la doc. del paquete ade4, algo debe estar caído en CRAN ahora mismo.
Dos cosas sobre la metodología -aun desconociendo los detalles de cómo lo hace ade4:
El output de un PCA, los "pesos" de cada variable en las dimensiones de los componentes se interpretan como correlaciones, a mayor valor absoluto mayor asociación variable-componente. Ahora, como tales
2017 Aug 16
1
Bias-corrected percentile confidence intervals
Hi folks,
I'm trying to estimate bias-corrected percentile (BCP) confidence
intervals on a vector from a simple for loop used for resampling. I am
attempting to follow steps in Manly, B. 1998. Randomization, bootstrap
and monte carlo methods in biology. 2nd edition., p. 48. PDF of the
approach/steps should be available here:
https://wyocoopunit.box.com/s/9vm4vgmbx5h7um809bvg6u7wr392v6i9
If
2016 Apr 13
0
Decision Tree and Random Forrest
Tjats great that you are familiar and thanks for responding. Have you ever
done what I am referring to? I have alteady spent time going through links
and tutorials about decision trees and random forrests and have even used
them both before.
Mike
On Apr 13, 2016 5:32 PM, "Sarah Goslee" <sarah.goslee at gmail.com> wrote:
It sounds like you want classification or regression trees.
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)
2013 Jul 26
1
variación en los resultados de k medias (Alfredo Alvarez)
Buen día, no sé si estoy utilizando bien la lista, es la primera vez. Si lo
hago mal me corrigen por favor.
Sobre tu comentario Pedro, muchas gracias. Lo qeu entiendo con tu
sugerencia de set.seed es qeu de esa forma fijas los resultados, pero no
estoy seguro si otra agrupación funcione mejor. Es decir me interesa un
método de agrupación que genere la "mejor" agrupación y como los
2016 Apr 15
1
Decision Tree and Random Forrest
I need the output to have groups and the probability any given record in
that group then has of being in the response class. Just like my email in
the beginning i need the output that looks like if A and if B and if C then
%77 it will be D. The examples you provided are just simply not similar.
They are different and would take interpretation to get what i need.
On Apr 14, 2016 1:26 AM,
2010 Nov 30
3
pca analysis: extract rotated scores?
Dear all
I'm unable to find an example of extracting the rotated scores of a
principal components analysis. I can do this easily for the un-rotated
version.
data(mtcars)
.PC <- princomp(~am+carb+cyl+disp+drat+gear+hp+mpg, cor=TRUE, data=mtcars)
unclass(loadings(.PC)) # component loadings
summary(.PC) # proportions of variance
mtcars$PC1 <- .PC$scores[,1] # extract un-rotated scores of
2016 Apr 14
3
Decision Tree and Random Forrest
I still need the output to match my requiremnt in my original post. With decision rules "clusters" and probability attached to them. The examples are sort of similar. You just provided links to general info about trees.
Sent from my Verizon, Samsung Galaxy smartphone<div>
</div><div>
</div><!-- originalMessage --><div>-------- Original message
2011 Mar 22
1
Find Principal Component Score per year
Hi,
I am trying to calculate Principal Component Scores per id per year using
the psych package. The following lines provide the scores per obeservation
pca = data.frame(read.table(textConnection(" id year A B C D
1001 1972 64 56 14 23
1003 1972 60 55 62 111
1005 1972 57 51 10 47
1007 1972 59 49 7 10
1009 1972 65 50 9 32
1011 1972 52 58 3 5
1013
2011 Mar 03
2
PCA - scores
I am running a PCA, but would like to rotate my data and limit the
number of factors that are analyzed. I can do this using the
"principal" command from the psych package [principal(my.data,
nfactors=3,rotate="varimax")], but the issue is that this does not
report scores for the Principal Components the way "princomp" does.
My question is:
Can you get an
2012 Jan 18
2
computing scores from a factor analysis
Haj
i try to perform a principal component analysis by using a tetrachoric
correlation matrix as data input
tetra <- tetrachoric (image_na, correct=TRUE)
t_matrix <- tetra$rho
pca.tetra <- principal(t_matrix, nfactors = 10, n.obs = nrow(image_na),
rotate="varimax", scores=TRUE)
the problem i have is to compute the individual factor scores from the pca.
the code runs perfect
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!