Displaying 20 results from an estimated 4000 matches similar to: "Weighted 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
2006 May 03
2
mca id numbers
Is it possible to make disappear the id numbers from scatter.dudi (mc
analysis) ?
a <- as.factor(c(1, 2, 3, 2, 1))
b <- as.factor(c(3, 2, 3, 1, 1))
x <- as.factor(c(1, 2, 2, 1, 3))
y <- as.factor(c(2, 2, 3, 1, 1))
dat <- data.frame(a=a, b=b,x=x,y=y)
summary(dat)
dat
require(ade4)
dat.acm <- dudi.acm(dat, scann = FALSE, nf = 2)
scatter.dudi(dat.acm)
Thank you very much !
2007 Oct 16
2
Canberra distance
Hi,
I misunderstand the definition of Canberra distance in R.
On Internet and in function description pages of dist() from stats and
Dist() from amap, Canberra distance between vectors x and y, d(x,y), is :
d(x,y) = sum(abs(x-y)/(x+y))
But in use, through simple examples, we find that the formula is :
d(x,y) = (NZ + 1)/NZ * sum(abs(x-y)/(x+y))
with NZ = nb of pairs of coordinates that are
2003 Jan 30
3
Principal comp. scores in R
Hello, I am trying to run a PCA in R and I cannot get the PC scores for
each of the values. Using pcX <- princomp(X) then loadings(pcX) I can get a
listing of the eigenvectors but not the actual PC scores for each value in
the dataset. I greatly appreciate any help anyone can offer
Thanks
Ken
2006 Dec 05
1
Cummulative Variance in Correspondence Analysis (ADE4)
Hi all:
How can I calculate the cumulative variance (or variance for each component)
in correspondence analysis?
If were possible in ADE4 package
Thank you
-- Antonio Punzón Merino
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Fax: +34
2008 Apr 01
1
superimpose histogram on biplot
Hi all,
I've been trying to figure out how to superimpose a histogram on a
biplot that shows the relative contribution of each axis. I have
been using the NIPALS function (http://biomserv.univ-lyon1.fr/~dray/
files/softwares/nipals.R) to run principal component analyses. Here
is a toy example.
source("http://biomserv.univ-lyon1.fr/~dray/files/softwares/nipals.R")
2003 Jun 03
3
lda: how to get the eigenvalues
Dear R-users
How can I get the eigenvalues out of an lda analysis?
thanks a lot
christoph
--
Christoph Lehmann <christoph.lehmann at gmx.ch>
2007 Nov 16
1
Efficient way to compute power of a sparse matrix
Dear all,
I would like to compute power of a square non symmetric matrix. This is
a part of a simulation study. Matrices are quite large (e.g., 900 by
900), and contains many 0 (more than 99 %). I have try the function
mtx.exp of the Biodem package:
library(Biodem)
m <- matrix(0, 900, 900)
i <- sample(1:900, 3000, replace = T)
j <- sample(1:900, 3000, replace = T)
for(x in 1:3000)
2004 Nov 04
2
biplot drawing conc ellipses
Is there an option to draw concentration ellipses in biplots ? It seems
really nice to summarize large number of points of each group.
Cheers../ Murli
2006 Nov 10
2
Simplifying Sweave graphics
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2005 May 16
3
Mental Block with PCA of multivariate time series!
Please could someone point me in the right direction as I appear to be
having a total mental block with fairly basic PCA problem!
I have a large dataframe where rows represent independent
observations and columns are variables. I am wanting to perform PCA
sequentially on blocks of nrows at a time and produce a graphical output
of the loadings for the first 2 EOFs for each variable.
I'm sure
2007 Mar 28
2
Standardization Range
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indicato...
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2008 Apr 22
4
Modeling presence only data in R
Dear All,
I have a set of environental maps and presence-only points for some species.
How can I generate distributions models on R using these presence-only data?
What packages and functions can I use to do so?
Kind regards,
Miltinho
Brazil
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2005 Oct 11
1
STATIS
Hi, i'm having trouble using Statis in ADE4 package.
I want to study a matrix with 18x414...could any body help me?!?!'
Urgent
Thanks
Miguel Ribeiro
Portugal
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2005 Oct 24
1
Pb with function taxo2phylog (package ade4)
Hello
I'm using the package ade4 to obtain classification from a .txt file. I
use the following commands:
cronquist <- read.table("cronquist.txt", h = T, row.names = 8)
cronquist <- as.taxo(cronquist[7:1])
cro.phy <- taxo2phylog(cronquist)
in which cronquist.txt is a file with a classification of 218 genus of tree
species from french Guiana.
We I try to use the
2008 Feb 26
3
R package to perform Horn's parallel analysis
I am seeking information on whether anyone has written code to perform
Horn's parallel analysis (a procedure that informs the selection of the
proper number of components in PCA) in R.
Thank you in advance for any help you can provide. Please respond
off-list at the email address below.
Karen Douglas
*******************************************************************
Karen Douglas,
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?
2007 Apr 23
3
Help about princomp
Hello,
I have a problem with the princomp method, it seems stupid but I don't know
how to handle it.
I have a dataset with some regular data and some outliers. I want to
calculate a PCA on the regular data and get the scores for all data,
including the outliers. Is this possible on R?
Thank you for helping!!!
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2009 Oct 29
2
Rounding and printing
Hello,
I am trying to print a table with numbers all rounded to the same number of digits (one after the decimal), but R seems to want to not print ".0" for integers. I can go in and fix it one number at a time, but I'd like to understand the principle. Here's an example of the code. The problem is the 13th element, 21 or 21.0:
>nvb_deaths <- round(ss[,10]/100,digits=1)
2004 Jan 01
1
ade4
Dear All,
I am using the scatter.dudi finction in the 'ade4' package to produce
correspondence analysis (nice) plots.
I do not seem to figure out how to plot the raw coordinates only -- or column
coordinates only. I would appreciate any help in doing that.
Here is the example I am following -- from the package.
data(banque)
> banque.acm <- dudi.acm(banque, scann = FALSE, nf =