Displaying 20 results from an estimated 60000 matches similar to: "Functional Principal Components Analysis"
2008 Dec 11
2
Principal Component Analysis - Selecting components? + right choice?
Dear R gurus,
I have some climatic data for a region of the world. They are monthly averages
1950 -2000 of precipitation (12 months), minimum temperature (12 months),
maximum temperature (12 months). I have scaled them to 2 km x 2km cells, and
I have around 75,000 cells.
I need to feed them into a statistical model as co-variates, to use them to
predict a response variable.
The climatic
2007 Dec 26
2
Principal Components Analysis
Hi,
I do have a file that has 500000 columns and 40 rows. I want to apply PCA on
that data and this is what I did
h1<-read.table("Ccode.txt", sep='\t', header=F) # reads the data from the
file Ccode.txt
h2<-prcomp(na.omit(h1),center=T)
but I am getting the following error
"Error in svd(x, nu = 0) : 0 extent dimensions"
I appreciate if someone can help
2006 Nov 16
1
Problems with principal components analysis PCA with prcomp
Dear friends,
I am beginning to use R software in my academic research and I'm having some
problems regarding the use of PCA.
I have a table with 24445 rows and 9 columns, and I used the function
prcomp() to do the analysis.
Working with an example?:
x<-read.table("test.txt", header=T)
row.names(x)<-x[,1]
x<-x[,-1]
require(stats)
pca<-prcomp(x, scale=T)
names(pca)
##
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
2014 Jun 19
2
Principal component analysis with EQUAMAX rotation
Hello,
I need to do a principal component analysis with EQUAMAX-rotation.
Unfortunately the function principal() I use normally for PCA does not offer
this rotation specification. I could find out that this might be possible
somehow with the package GPArotation but until now I could not figure out
how to use this in the principal component analysis.
Maybe someone can give an example on how to do
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
2002 Dec 09
2
Principal component analysis
Dear R users,
I'm trying to cluster 30 gene chips using principal component analysis in
package mva.prcomp. Each chip is a point with 1,000 dimensions. PCA is
probably just one of several methods to cluster the 30 chips. However, I
don't know how to run prcomp, and I don't know how to interpret it's output.
If there are 30 data points in 1,000 dimensions each, do I have to
2012 Feb 29
2
Principal Component Analysis
Dear R buddies,
I’m trying to run Principal Component Analysis, package
princomp: http://stat.ethz.ch/R-manual/R-patched/library/stats/html/princomp.html.
My question is: why do I get different results with pca =
princomp (x, cor = TRUE) and pca = princomp (x, cor = FALSE) even when I
standardize variables in my matrix?
Best regards,
Blaž Simčič
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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
2011 Jul 29
1
Limited number of principal components in PCA
Hi all,
I am attempting to run PCA on a matrix (nrow=66, ncol=84) using 'prcomp'
(stats package). My data (referred to as 'Q' in the code below) are
separate river streamflow gaging stations (columns) and peak instantaneous
discharge (rows). I am attempting to use PCA to identify regions of that
vary together.
I am entering the following command:
2011 May 04
1
Outlier removal by Principal Component Analysis : error message
Hi,
I am currently analysis Raman spectroscopic data with the hyperSpec package.
I consulted the documentation on this package and I found an example
work-flow dedicated to Raman spectroscopy (see the address :
http://hyperspec.r-forge.r-project.org/chondro.pdf)
I am currently trying to remove outliers thanks to PCA just as they did in
the documentation, but I get a message error I can't
2012 Jul 25
2
Obtain residuals from a Principal Component Analysis
Hi everyone,
I am relatively new to R, and I need to perform the principal components
analysis of a data matrix. I know that there are a bunch of methods to do it
(dudi.pca, princomp, prcomp...) but I have not managed to find a method that
can return the residuals obtained by retaining X principal components of the
original data, as this MATLAB function can do: http://is.gd/6WeUFF
Suggestions?
2005 Apr 11
1
plotting Principal components vs individual variables.
At the cost of breaking the thread I'm going to change your subject and
replace 'Principle' by 'Principal'. I just can't stand it any longer...
OK, here is how I would solve your other problems. First put
> wh <- c("USA", "New Zealand", "Dominican Republic",
"Western Samoa", "Cook Islands")
> ind
2007 Jan 30
2
R and S-Plus got the different results of principal component analysis from SAS, why?
Dear Rusers,
I have met a difficult problem on explaining the differences of principal
component analysis(PCA) between R,S-PLUS and SAS/STATA/SPSS, which wasn't
met before.
Althought they have got the same eigenvalues, their coeffiecients were
different.
First, I list my results from R,S-PLUS and SAS/STATA/SPSS, and then show
the original dataset, hoping sb. to try and explain it.
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
2005 Jul 21
1
principal component analysis in affy
Hi,
I have been using the prcomp function to perform PCA on my example microarray data, (stored in metric text files) which looks like this:
1a 1b 1c 1d 1e 1f ...................................................4r 4s 4t
g1 1.2705 1.2766 ...........................................................2.0298
g2 0.1631
2007 Feb 13
1
Questions about results from PCAproj for robust principal component analysis
Hi.
I have been looking at the PCAproj function in package pcaPP (R 2.4.1) for
robust principal components, and I'm trying to interpret the results. I
started with a data matrix of dimensions RxC (R is the number of rows /
observations, C the number of columns / variables). PCAproj returns a list
of class princomp, similar to the output of the function princomp. In a
case where I can
2007 Dec 07
0
fda, version 1.2.3
fda 1.2.3
========================
Version 1.2.3 of the fda package has just been released. This version adds to
previous versions a script to create most of the figures of chapter 6 of
"Applied Functional Data Analysis" by Ramsay and Silverman. Other changes
offer simpler calls to time warping / registration and functional principal
component functions.
The fda package supports the
2012 May 18
1
Finding the Principal components
Dear all,
I am trying to find the PCs of a spatial data set (single
variable). I want to calculate the PCs at each Lat-Lon location.
The* 'princomp'* command gives the approximate standardized data
(i.e* pca$scores*), stranded deviation ..etc. I tried*
'pca$loadings'*also, but it giving value 1 all time.
Then I tried manually(without using* princomb*
2009 Apr 03
1
Weighted principal components analysis?
Hello R-ers,
I'm trying to do a weighted principal components analysis. I couldn't find any such option with princomp or prcomp. Does anyone know of a package or way to do this?
More specifically, the observations I'm working with are averages from populations of varying sizes. I thus need to weight the observations by sample size. Ideally I could apply these weights at the cell