similar to: Eigenvectors and values in R and SAS

Displaying 20 results from an estimated 130 matches similar to: "Eigenvectors and values in R and SAS"

2003 Mar 26
1
Solving equations
Hello, Does somebody knows if there exists a function which solves a set of equation, say f(vars), for the variables vars (similar to Solve in mathematica). The functions I am considering are of the form f(t) ~ A*exp(B*t), where A and B are matrices. Thanks Thomas
2010 Nov 10
2
prcomp function
Hello, I have a short question about the prcomp function. First I cite the associated help page (help(prcomp)): "Value: ... SDEV the standard deviations of the principal components (i.e., the square roots of the eigenvalues of the covariance/correlation matrix, though the calculation is actually done with the singular values of the data matrix). ROTATION the matrix of variable loadings
2010 Sep 29
1
Fitting a half-ellipse curve
Dear mailing list, I have following array: X2 Y2 [1,] 422.7900 6.0 [2,] 469.8007 10.5 [3,] 483.9428 11.0 [4,] 532.4917 25.5 [5,] 596.1942 33.5 [6,] 630.8496 40.5 [7,] 733.2996 45.0 [8,] 946.4779 32.0 [9,] 996.8068 35.5 [10,] 1074.3310 23.0 I do afterwards the following: plot.new() plot.window(xlim=c(min(X1)-50,max(X1)+50),
2007 Aug 12
1
Write values on y axe
Hi, I have values on y axe from 0.0001 to 3.086. When I do plot I have writen values: 0.001, 0.050,1.000 ..., but how I can write on graph the minimum value and maximum value, with all decimals (I don't want to use the format 1e-0x)? I am using log scale. For example, if I have the values: 0.0001 0.0015 0.0256 0.0236 .... 0.0201 2.9668 3.0086 I need have each 'x' value put on y axe,
2005 Dec 04
1
Understanding nonlinear optimization and Rosenbrock's banana valley function?
GENERAL REFERENCE ON NONLINEAR OPTIMIZATION? What are your favorite references on nonlinear optimization? I like Bates and Watts (1988) Nonlinear Regression Analysis and Its Applications (Wiley), especially for its key insights regarding parameter effects vs. intrinsic curvature. Before I spent time and money on several of the refences cited on the help pages for "optim",
2006 May 19
4
why no multiple submit?
is it by design? is it standard? how do you give users multiple actions on a form? -- Posted via http://www.ruby-forum.com/.
2002 Nov 26
3
dovecot and pop3
Dear dovecotters: I'm becoming interested in dovecot as a replacement for UW-IMAPD. Any project that claims it's the "postfix of ____ servers" deserves a looksee. If indeed I were to going to switch at some point, I'd need to replace the UW POP3 server (which is a part of the UW package). I would prefer one that actually used the dovecot IMAP server instead of going to
2008 Jun 03
3
matlab eigs function in R
Hello Does anybody know how one can compute d largest eigenvalues/eigenvectors in R, like in MATLAB eigs function ? eigen function computes all eigenvectors/eigenvalues, and they are slightly different than those generated by matlab eigs. Thanks in advance -- View this message in context: http://www.nabble.com/matlab-eigs-function-in-R-tp17619641p17619641.html Sent from the R help mailing list
2011 Jul 28
1
sorting data from dataframe with oter dataframe
Hi, the subject isn't define well the problem, so i'll explain it in detail: i've got a csv.file with data on number of factors (every column got the name of the factor as header and the data below). on another csv file, i've got the factors sorted by their type. for example- c1=read.csv('C:/R/c1.csv', header= TRUE) urrDate A_XS b_XS c_XS
2023 Mar 11
3
Multiple Assignment built into the R Interpreter?
Dear R Core, working on my dynamic factor modelling package, which requires several subroutines to create and update several system matrices, I come back to the issue of being annoyed by R not supporting multiple assignment out of the box like Matlab, Python and julia. e.g. something like A, C, Q, R = init_matrices(X, Y, Z) would be a great addition to the language. I know there are several
2010 Mar 19
1
Howto get unnormalized eigenvectors?
Hi, I try to calculate the angle between two first eigenvectors of different covariance matrices of biological phenotypic traits for different populations. My issue here is, that all possibilities to do so seem to normalize the eigenvectors to length 1. Although the helpfile of eigen() states, that using eigen(, symmetric = FALSE, EISPACK =TRUE) skips normalization this is (I guess) not applicable
2001 Sep 21
1
Request for Help: Rotation of PCA Solution or Eigenvectors
Dear R Helper, I am writing because I seek to perform a varimax rotation on my Principal Components Analysis (PCA) solution. (I have been performing PCA's using the eigen command in R.) If you can tell me how to perform this rotation when I use the eigen command (or the princomp command) I would be thrilled. Thanks so much! Wendy Treynor Ann Arbor, MI USA
2004 Jun 22
0
prcomp & eigenvectors
I have the following situation I want to analyse with prcomp. Each subject has a curve called the contrast sensitivity function (CSF). This curve's overall shape is due to the additive output of 3 "channels" (eigenvectors). #this shows 3 SF channels; net CSF = c1 + c2+c3 x<-1:100 c1<-dnorm(x,mean=20,sd=20) c2<-dnorm(x,mean=50,sd=20) c3<-dnorm(x,mean=80,sd=20)
2003 Jun 09
1
understanding eigen(): getting non-normalized eigenvectors
Hi, dear R pros I try to understand eigen(). I have seen, that eigen() gives the eigenvectors normalized to unit length. What shall I do to get the eigenvectors not normalized to unit length? E.g. take the example: A [,1] [,2] V1 0.7714286 -0.2571429 V2 -0.4224490 0.1408163 Calculating eigen(A) "by hand" gives the eigenvectors (example from Backhaus,
2008 Jul 08
1
Help with eigenvectors
Hi everybody, I have some problems with the function eigen. I have a square matrix and I want to calculate the eigenvalues and eigenvectors. I apply the function eigen and I get it, however when I solve the same problem in Statistica software, I realise that some eigenvectors are the opposite. How can I get the same values? Thanks in advance [[alternative HTML version deleted]]
2011 May 28
1
prcomp & eigenvectors ... ??
Hi ... Please could you help with probably a very simple problem I have. I'm completely new to R and am trying to follow a tutorial using R for Force Distribution Analysis that I got from ... http://projects.eml.org/mbm/website/fda_gromacs.htm. Basically, the MDS I preform outputs a force matrix (.fm) from the force simulation I perform. Then, this matrix is read into R and prcomp is
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,
2002 Nov 05
2
eigenvectors order
Hi, How the eigenvectors output by the eigen() function are ordered. The first column corresponds to the largest eigenvalue? or is the last column as in Octave? I'm performing a spatial-temporal analysis of some climatic variables so my matrices are MxN (locations*time)and I'm looking for the leading EOF's. As I have understand the eigenvectors columns represent those EOF's
2013 Mar 14
2
Same eigenvalues but different eigenvectors using 'prcomp' and 'principal' commands
Dear all, I've used the 'prcomp' command to calculate the eigenvalues and eigenvectors of a matrix(gg). Using the command 'principal' from the 'psych' packageĀ  I've performed the same exercise. I got the same eigenvalues but different eigenvectors. Is there any reason for that difference? Below are the steps I've followed: 1. PRCOMP #defining the matrix
2011 Nov 14
0
Fwd: How to compute eigenvectors and eigenvalues?
Inicio del mensaje reenviado: > De: Arnau Mir <arnau.mir@uib.es> > Fecha: 14 de noviembre de 2011 13:24:31 GMT+01:00 > Para: Martin Maechler <maechler@stat.math.ethz.ch> > Asunto: Re: [R] How to compute eigenvectors and eigenvalues? > > Sorry, but I can't explain very well. > > > The matrix 4*mp is: > > 4*mp > [,1] [,2] [,3] > [1,]