Displaying 20 results from an estimated 900 matches similar to: "Finding the Principal components"
2007 Apr 14
6
[LLVMdev] Regalloc Refactoring
On Thu, 12 Apr 2007, Fernando Magno Quintao Pereira wrote:
>> I'm definitely interested in improving coalescing and it sounds like
>> this would fall under that work. Do you have references to papers
>> that talk about the various algorithms?
>
> Some suggestions:
>
> @InProceedings{Budimlic02,
> AUTHOR = {Zoran Budimlic and Keith D. Cooper and Timothy
2010 Sep 26
8
the function doesn´t work
hey, my function doesn?t work. can somebody help me?
the graphic doesn?t work and also the function. thnx a lot.
N=10
n=100
p_0=c(1/5,1-1/5)
power = function(p,m) {
set.seed(1000)
H=matrix(0,nrow=N,ncol=1)
for(i in 1:N) {
x <- matrix(rnorm(n, 0, 0.5), ncol = m)
y <- matrix(rnorm(n, 0, 0.8), ncol = m)
l <- diag(cor(x, y))
q_1 = qnorm(0.05, 0, 0.05)
q_2 = qnorm(1 - 0.05, 0, 0.05)
2010 Sep 25
1
(no subject)
hi how can i plot now this function??? have to be m= 2??? because of the dimensions?thanks for ur help
myfun <- function(n, m, alpha = .05, seeder = 1000) {
set.seed(seeder)
x <- matrix(rnorm(n, 0, 0.5), ncol = m)
y <- matrix(rnorm(n, 0, 0.8), ncol = m)
l <- diag(cor(x, y))
cat("Correlations between two random variables \n", l, fill = TRUE)
gute
2010 Sep 25
3
3D plot
hey, how can i plot this function??? thanks for ur help
n=1000
m=2
k=n/m
N=100
myfun <- function(n, m, alpha = .05, seeder = 1000) {
l=matrix(0,nrow=m,ncol=N)
for(i in 1:N){
set.seed(i)
for(j in 1:m){
x=rnorm(n,0,0.5)
y=rnorm(n,0,0.8)
l[j,i]=cor((x[(((j-1)*k)+1):(((j-1)*k)+k)]),
(y[(((j-1)*k)+1):(((j-1)*k)+k)]))
}
}
for(i in 1:N){
for (j in 1:m){
gute <- function() {
q_1 <-
2009 Jan 12
1
re tail case-pack ordering problem - can R help?
I'm a programmer, not a mathmatician. I heard about R, and I'm wondering if
anyone can tell me if there is an existing R function that can help with a
problem we're currently trying to find an algorithm for. If R is not the
answer, but you can recommend a known algorithm, that would help a lot!
I'm on a project in a retail corporation, working on a program to assist
retail buyers
2011 Aug 10
3
[LLVMdev] Handling of pointer difference in llvm-gcc and clang
Hi,
We are developing a bounded model checker for C/C++ programs
(http://baldur.iti.kit.edu/llbmc/) that operates on LLVM's intermediate
representation. While checking a C++ program that uses STL containers
we noticed that llvm-gcc and clang handle pointer differences in
disagreeing ways.
Consider the following C function:
int f(int *p, int *q)
{
return q - p;
}
Here's the
2011 Aug 10
0
[LLVMdev] Handling of pointer difference in llvm-gcc and clang
Hi Stephan,
> We are developing a bounded model checker for C/C++ programs
> (http://baldur.iti.kit.edu/llbmc/) that operates on LLVM's intermediate
> representation. While checking a C++ program that uses STL containers
> we noticed that llvm-gcc and clang handle pointer differences in
> disagreeing ways.
>
> Consider the following C function:
> int f(int *p, int *q)
2005 Mar 31
1
loadings or summary in Principal components
May be a simple question, but not understanding why in princomp I get different results for loadings and summary for my eigenvectors and eigenvalues.
When I use pc.cr$loadings using the USArrests dataset the proportion of variance is equal for each of the components, but when summary(pc.cr) is used the proportion of variance is showing different proportions. My question is why do they differ? I
2007 Apr 24
1
Matrix: how to re-use the symbolic Cholesky factorization?
I have been playing around with sparse matrices in the Matrix
package, in particularly with the Cholesky factorization of matrices
of class dsCMatrix. And BTW, what a fantastic package.
My problem is that I have to carry out repeated Cholesky
factorization of a spares symmetric matrices, say Q_1, Q_2, ...,Q_n,
where the Q's have the same non-zero pattern. I know in this case one
does
2005 Nov 17
1
Principal Components Analysis (PR#8320)
Full_Name: Sahotra Sarkar
Version: 2.2.0
OS: Windows XP Professional
Submission from: (NULL) (146.6.130.180)
The following two commands should give the same results for the eigenvectors but
do not (there is a sign reversal for the first one):
> summary(princomp(bumpus),loading = TRUE)
Importance of components:
Comp.1 Comp.2 Comp.3 Comp.4 Comp.5
2010 Jun 15
1
Getting the eigenvectors for the dependent variables from principal components analysis
Dear listserv,
I am trying to perform a principal components analysis and create an output table of the eigenvalues for the dependent variables. What I want is to see which variables are driving each principal components axis, so I can make statements like, "PC1 mostly refers to seed size" or something like that.
For instance, if I try the example from ?prcomp
> prcomp(USArrests,
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:
2003 Feb 27
0
spatial evolution and variance after rotation of Principal components
Dear R users,
I have been doing rotation on Principal components analyse, with varimax
function and promax. Following those changes, I cannot find now how to get
the spatial evolution and the variance. Indeed, with the function princomp
that has been used to get the principal components, arguments such as $scores
and $sdev were available to get the spatial evolution and the variance, with
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
2006 Mar 30
0
Functional Principal Components Analysis
Hi,
I am interested in using functional principal component analysis (Functional
PCA). However, in the help of fda package, it does not have an example of
pca.fd function.
Does anyone have the example of pca.fd function?
Thank you very much.
Sincerely yours,
Nantachai
2011 Apr 01
1
principal components
HI all,
I am trying to compute the EOF of a matrix using prcomp but unable to get
the expansion co-efficients.
is it possible using prcomp or are there any other methods
thanks
nuncio
--
Nuncio.M
Research Scientist
National Center for Antarctic and Ocean research
Head land Sada
Vasco da Gamma
Goa-403804
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2012 Oct 14
1
plotting principal components on geographic map
Dear all,
I have a dataset representing several geographical points (locations), each
one having a specific value after performing a PCA.
Now I'm trying to understand how to separately represent on a geographic
map (of Europe) the pattern of PC1,2, ecc.with colors (e.g.heatmap)
I have to add that the dataset includes relatively few points. Therefore, I
would also like to interpolate the values
2008 Nov 24
0
plot Principal Components axes on original data
Hello
I'm writing an example PCA analysis for some students. I've done PCA on a
2-column matrix to show it at the most simple form (a rotation of two
axes). I can't, however, figure out how to plot the rotated axes as lines
over top of the original data plotted on the x-y. Does anyone know how to
do this? It will be a good way to show how the rotated axes describing the
most
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
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2012 Feb 27
3
Principal Components for matrices with NA
Hello,
I have a matrix with 267 columns, all rows of which have at least one
column missing (NA).
All three methods i've tried (pcs, princomp, and prcomp) fail with either
"Error in svd(zsmall) : infinite or missing values in 'x'" (latter two)
or
"Error in cov.wt(z) : 'x' must contain finite values only"
The last one happens because of the check
if