Displaying 20 results from an estimated 900 matches similar to: "Cases as Variables in Principal Component Analysis?"
2003 Jul 11
2
Nonliner Rgression using Neural Nnetworks
Hi,
I am an old hand at chemistry but a complete beginner at statistics
including R computations.
My question is whether you can carry out nonlinear
multivariate regression analysis in R using neural networks, where the
output variable can range from -Inf to + Inf., unlike discriminant
analysis where the output is confined to one or zero. The library nnet
seems to work only in the latter
2003 Aug 19
3
On the Use of the nnet Library
Dear List,
I am trying to solve a problem by the neural network method(library:
nnet). The problem is to express Weight in terms of Age , Sex and Height
for twenty people. The data frame consists of 20 observations with four
variables: Sex, Age, Height and Weight. Sex is treated as a factor, Age
and Weight are variables normalized to unity, as usual. I wanted to
construct a neural network, and so
2006 Apr 05
1
Correlation of coefficients?
Hi R users!
One thing I cannot understand with R is the frequently appearing "
Correlation of coefficients". I do not find a through going explanation
of this concept either on the help pages of R or on the internet. A
Google search has shown many examples of R/S-Plus outputs but no
explanations of meaning.
I am afraid this turns out to be a silly and unworthy question. Would
anyone be
2008 May 13
9
A Very Simple Question
On 5/13/2008 10:27 AM, Yukihiro Ishii wrote:
> Hi Rusers!
>
> I am ashed of asking such a simple question.
>
> X<-matrix(rnorm(24), 4)
> X0<-apply(X,2,mean)
>
> What I want is a matrix which consists of colums such as X[,1]--X0[1].
>
> X-X0 doesn't work.
>
> Perhaps apply function?
scale(X, scale=FALSE)
?scale
> Thanks in advance.
>
>
2005 Feb 07
1
[matz@ruby-lang.org: Re: Performance of CGI::Cookie / SimpleDelegator fix]
Matz claims 1.8.3 might be released in April. If we''re lucky, maybe it
will have the Windows socket connection fix applied. (Although the patch
has been hanging around since last June... but maybe they just needed
some prodding. :) )
Then RubyTorrent will be much more usable on Windows.
----- Forwarded message from Yukihiro Matsumoto <matz@ruby-lang.org> -----
Date: Tue, 8 Feb
2008 Apr 09
1
chi-square test
Hi R-users,
I would like to find the goodness of fit using Chi-suare test for my data below:
xobs=observed data, xtwe=predicted data using tweedie, xgam=predicted data using gamma
> xobs <- c(223,46,12,5,7,17)
> xtwe <- c(217.33,39,14,18.33,6.67,14.67)
> xgam <- c(224.67,37.33,12.33,15.33,5.33,15)
> chisq.test(xobs, xtwe = xtwe, rescale.p = TRUE)
Error in chisq.test(xobs,
2004 Feb 22
0
hello !!
Hi !!
<p> I am just now reading Vorbis I specifications .
I ahve some quries in that regading overlap add and sqaure polar mapping
.
I am writting this mail with the hope that ,some one will resolve my
quries.
<p> 1. After IMDCT , to remove the aliasing , we do overlap and add . For
that the
window should have following properties ------------->
hk =
2007 Feb 02
0
Re: Dom0 and DomU can connect only to local network
Hello.
This is a follow by myself. I added the following lines (with +
marking) to /etc/network/interfaces and problem is solved.
On 2007/01/31, at 20:14, Toshinao Ishii wrote:
>
> auto lo
> iface lo inet loopback
>
+ auto eth0
+ iface eth0 inet manual
> # The primary network interface
> auto xenbr0
> iface xenbr0 inet static
> address 10.140.2.84
>
2011 Oct 19
0
Fukuoka Ruby Night
Ruby event on November 3, 2011 at MacKenzie Room, Stanford University.
Program will include, 1) keynote speeches by Yukihiro “Matz” Matsumoto
and Derek Collison, CTO, VMware Inc. and 2)Silicon Valley Ruby
Innovator Award Competition, a preliminary competition for the 2012
Fukuoka Ruby Award.
Please check the details from the following link and register for the
event.
2006 Mar 27
6
Fwd: Tricky block args
We in the JRuby project are working to get Rails to work successfully.
However, the array-indexed block parameter is not something currently
supported in JRuby:
x = {}
[1,2].each {|x[:foo]|}
This is not used extensively in the Rails code, but it''s used enough to
cause things to break in JRuby. We have been modifying the above to use a
temporary local variable, but obviously
2006 Feb 27
1
question about Principal Component Analysis in R?
Hi all,
I am wondering in R, suppose I did the principal component analysis on
training data set and obtain the rotation matrix, via:
> pca=prcomp(training_data, center=TRUE, scale=FALSE, retx=TRUE);
Then I want to rotate the test data set using the
> d1=scale(test_data, center=TRUE, scale=FALSE) %*% pca$rotation;
> d2=predict(pca, test_data, center=TRUE, scale=FALSE);
these two
2006 Apr 16
1
How to do varimax rotation for principal component based factor analysis, any packages?
Dear R users
the factanal pacakge is always MLE, which package can do varimax
rotation with the results from princomp ?
thank you
yong
2013 Dec 17
1
Polychoric Principal Component Analysis (pPCA)
I have data set with binary responses. I would like to
conduct polychoric principal component analysis (pPCA). I know there are several packages used in PCA but I could not find one that directly estimate pPCA and graph the individuals and variables maps. I will appreciate any help that expand these reproducible scripts.
#How to conduct polychoric principal component analysis pPCA using
#either
1998 Nov 07
1
principal component plots
Hi:
How i can make principal component plots with R.
thanks
Jorge
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2001 Jan 11
0
Principal component?
Hi everyone,
I did a principal component analysis (princomp) on a dataset I have, I
plotted the first two columns and labeled the points by their index number.
I observed that most index sequences (points 50:65 for example) kind of form
arc shape trajectories on the graph (even loops), some of those seem to
converge at some particular location and those specific patterns just happen
to have some
2006 Nov 28
2
factor analysis using Principal Component Method
Is there any R function to perform factor analysis using Principal
Component Method?
why factanal() method is " always "mle" " ?
2008 Feb 14
1
Principal component analysis PCA
Hi,
I am trying to run PCA on a set of data with dimension 115*300,000. The
columns represnt the snps and the row represent the individuals. so this is
what i did.
#load the data
code<-read.table("code.txt", sep='\t', header=F, nrows=300000)
# do PCA #
pr<-prcomp(code, retx=T, center=T)
I am getting the following error message
"Error: cannot allocate vector of
2009 Aug 03
1
principal component analysis for class variables
Dear Forum,
I have a class variable 1 (populations A-E), and two other class variables,
variable 2 and variable 3. What I want is to see if the combination of var 2
and var 3, will give me a pattern that allows to distinguish populations.
I found several packages like ade4, with pcaiv function and factoMineR. but
there are not working. Using the ade4 package, when I try to build the pca:
pca1
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)
2012 Aug 23
1
Accessing the (first or more) principal component with princomp or prcomp
Hi ,
To my knowledge, there're two functions that can do principal component
analysis, princomp and prcomp.
I don't really know the difference; the only thing I know is that when
the sample size < number of variable, only prcomp will work. Could someone
tell me the difference or where I can find easy-to-read reference?
To access the first PC using princomp: