Displaying 17 results from an estimated 17 matches similar to: "info : Manova - eigenvector analysis and canonical analysis"
2005 Aug 11
1
About sampleenc and sampledec in appendix B
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2005 Aug 10
0
About sampleenc and sampledec in appendix B
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2012 Apr 27
2
find the eigenvector corresponding to the largest eigenvalue
Hi,
If I use the eigen() function to find the eigenvalues of a matrix, how can I find the eigenvector corresponding to the largest eigen value?
Thanks!
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2007 Nov 27
0
Function to calculate eigenvector bootstrap error
Hi everybody,
I need help in writing a statistical function for bootstrap. Suppose m is a matrix with n cols and p rows, my original data. What I want to do is a bootstrap (using boot from package boot) on eigenvectors from a PCA done on m with a statistic function calculating the eigenvector bootstrap error ratio.
If R = number of bootstrap replicates, then my function should look something
2010 Sep 30
0
igraph / eigenvector centrality score
Hi to all,
I have two graphs with the same number of nodes but with different
connectivities and also with a different number of clusters.
The two graphs represent the same "system" under different "conditions" and
then there is a one-to-one correspondence between a given node in the two
graphs.
It is correct to use the eigenvector centrality score as a measure of the
relevance
2010 Jun 12
1
Fast way to compute largest eigenvector
Hello all,
I was wondering if there is a function in R that only computes the eigenvector
corresponding to the largest/smallest eigenvalue of an arbitrary real matrix.
Thanks
Minh
--
Living on Earth may be expensive, but it includes an annual free trip
around the Sun.
2004 Feb 12
1
left eigenvector
Dear All,
how do I compute the left eigenvector of a matrix? I gather that "eigen"
computes the right eigenvectors...
Regards,
Federico Calboli
--
=================================
Federico C. F. Calboli
PLEASE NOTE NEW ADDRESS
Dipartimento di Biologia
Via Selmi 3
40126 Bologna
Italy
tel (+39) 051 209 4187
fax (+39) 051 251 208
f.calboli at ucl.ac.uk
2009 Apr 23
1
the definition of eigenvector in R
Dear All
i have a little puzzle about eigenvector in the R.
As we know that the eigenvector can be displayed on several form.
For example
A=matrix(c(1,2,4,3),2,2)
if we want to get the eigenvalue and eigenvector, the code followed
eigen(A)
$values
[1] 5 -1
$vectors
[,1] [,2]
[1,] -0.7071068 -0.8944272
[2,] -0.7071068 0.4472136
however, we also can calculate the vector matrix
2009 Apr 24
1
the puzzle of eigenvector and eigenvalue
Dear all
I am so glad the R can provide the efficient calculate about
eigenvector and eigenvalue.
However, i have some puzzle about the procedure of eigen.
Fristly, what kind of procedue does the R utilize such that the eigen
are obtained?
For example, A=matrix(c(1,2,4,3),2,2)
we can define the eigenvalue lamda, such as
det | 1-lamda 4 | =0
| 2 3-lamda |
then
2005 Jan 29
1
Bootstrapped eigenvector
Hello alls,
I found in the literature a technique that has been evaluated as one of the
more robust to assess statistically the significance of the loadings in a
PCA: bootstrapping the eigenvector (Jackson, Ecology 1993, 74: 2204-2214;
Peres-Neto and al. 2003. Ecology 84:2347-2363). However, I'm not able to
transform by myself the following steps into a R program, yet?
Can someone could help
1999 Apr 20
2
eigenvalue/eigenvector calculations
Some of you may have seen a message on s-news by Stefan Steinhaus
regarding his paper on "Comparison of mathematical programs for data
analysis". He compares S-PLUS 4.5 with several other programs. He
does not include R in the comparisons. On p. 28 of his report he
gives the URL the Auckland site along with URL's for two other systems
but comments that "I didn't received
2007 Jun 29
4
Dominant eigenvector displayed as third (Marco Visser)
Dear R users & Experts,
This is just a curiousity, I was wondering why the dominant eigenvetor and eigenvalue
of the following matrix is given as the third. I guess this could complicate automatic selection
procedures.
0 0 0 0 0 5
1 0 0 0 0 0
0 1 0 0 0 0
0 0 1 0 0 0
0 0 0 1 0 0
0 0 0 0 1 0
Please
2003 Feb 06
6
Confused by SVD and Eigenvector Decomposition in PCA
Hey, All
In principal component analysis (PCA), we want to know how many percentage
the first principal component explain the total variances among the data.
Assume the data matrix X is zero-meaned, and
I used the following procedures:
C = covriance(X) %% calculate the covariance matrix;
[EVector,EValues]=eig(C) %%
L = diag(EValues) %%L is a column vector with eigenvalues as the elements
percent
2002 Feb 04
2
maximal dataset size
Hi, there,
I am using PC window version R and dealing with big dataset usually. May
anyone let me whether the maximal dataset size in R is limited by computer
memory or hard drive capacity?
Thanks in advance.
Yiling Cheng, M.D., Ph.D.
Project Manager
The Cooper Institute for Aerobics Research
12330 Preston Road, Dallas, Texas 75230
phone: (972) 3413248; Fax: (972) 3413224
2009 Jan 19
3
bootstrapped eigenvector method following prcomp
G'Day R users!
Following an ordination using prcomp, I'd like to test which variables
singnificantly contribute to a principal component. There is a method
suggested by Peres-Neto and al. 2003. Ecology 84:2347-2363 called
"bootstrapped eigenvector". It was asked for that in this forum in
January 2005 by J?r?me Lema?tre:
"1) Resample 1000 times with replacement entire
2007 Jan 19
1
Error in basehaz function ?
Hello R-users.
I believe that the way basehaz (in the survival package) compute the
baseline hazard function is false.
I come to question this function when it gives me hazard probabilities
greater than 1.
Looking at the code I think I've localised the error :
hazard probability is computed as :
H <- -log(surv)
but it seems to me that hazard probabilities is rather an instantaneous
2012 Nov 23
2
[LLVMdev] [cfe-dev] costing optimisations
On 23.11.2012, at 15:12, john skaller <skaller at users.sourceforge.net> wrote:
>
> On 23/11/2012, at 5:46 PM, Sean Silva wrote:
>
>> Adding LLVMdev, since this is intimately related to the optimization passes.
>>
>>> I think this is roughly because some function level optimisations are
>>> worse than O(N) in the number of instructions.
>>