similar to: Re: Help : generating correlation matrix with a particular

************************************************************ Important: We would draw your attention to the notices at the bottom of this e-mail, particularly before opening and reviewing any file attachment(s). ************************************************************ Martin, Thank you for letting us know about posdefify. It does do exactly what the Rebonato paper recommended and

Hi, I would like to generate a correlation matrix with a particular structure. For example, a 3n x 3n matrix : A_(nxn) aI_(nxn) bI_(nxn) aI_(nxn) A_(nxn) cI_(nxn) aI_(nxn) cI_(nxn) A_(nxn) where - A_(nxn) is a *specified* symmetric, positive definite nxn matrix. - I_(nxn) is an identity matrix of order n - a, b, c are (any) real numbers Many attempts have been unsuccessful because a

Dear All, I have attempted to install the R-Excel Interface with poor results. The version of R is 1.6.1, the version of R-Excel is 1.0, the version of COM is 0.99. All of these were downloaded Monday, 6 January 2003. R (version 1.6.1) is installed on the machine and appears to run correctly on its own. The computer is a Compaq Pentium 4 machine with 128 meg of RAM running Windows 2000 and

1. Martin Maechler's comments should be taken as replacements for anything I wrote where appropriate. Any apparent conflict is a result of his superior knowledge. 2. 'eigen' returns the eigenvalue decomposition assuming the matrix is symmetric, ignoring anything in m[upper.tri(m)]. 3. The basic idea behind both posdefify and nearPD is to compute the

Dear all, Has someone implemented in R (or any other language) Knol DL, ten Berge JMF. Least-squares approximation of an improper correlation matrix by a proper one. Psychometrika, 1989, 54, 53-61. or any other similar algorithm? Best regards Jens Oehlschl?gel Background: I want to factanal() matrices of polychoric correlations which have negative eigenvalue. I coded Highham 2002

Anyone have any idea on this. I wanted to separate out my VirtualBox VDIs so that I could activate compression on the rest of the parent directory structure so I created a ZFS filesystem under my user directory. mv .VirtualBox .VirtualBox_orig zfs create /export/home/user/.VirtualBox zfs create /export/home/user/.VirtualBox/VDI zfs set compression=off /export/home/user/.VirtualBox/VDI zfs set

I have a covariance matrix that is not positive semi-definite matrix and I need it to be via some sort of adjustment. Is there any R routine or package to help me do this? Thanks, Roger [[alternative HTML version deleted]]

Dear R-users, I am having trouble constructing nxn matrices involving calculations& conditions based on other tables. Below I describe a simple example of what I am trying to do: Given the Table A (n x m): Species1 Species2 X A1,1 A1,2 Y A2,1 A2,2 Z A3,1 A3,2 I want to create a matrix M (n xn) X Y Z X - M1,2 M1,3 Y M2,1 - M2,3 Z M3,1 M3,2 -

Hi all, I wonder if this kind of questions are ok in this list... Quick question: What does it mean than the rank of the QR decomposition of a NxN matrix is N-1 ? m: NxN matrix qr(m)$rank equal to (N-1) Long version: I'm doing a manova on a matrix of 10 variables and 16 observations. > dim(tmp) [1] 16 10 > fit <- manova( tmp ~ treatment*mouse ) >results <-

Hi, I would like to enquire if by typing plot (lm(y~x)) would this show me the plot of the fitted line? I tried this function previously but I was only able to get the last 4 plots starting with Residuals vs fitted. Thank You. Melissa ************************************************************ JLT Risk Solutions Ltd 6 Crutched Friars, London EC3N 2PH. Co Reg No 1536540 Tel: (44) (0)20 7528

Hi, I would like to know how to extract the data from Excel Spreadsheet. Thank you very much. Melissa ************************************************************ JLT Risk Solutions Ltd 6 Crutched Friars, London EC3N 2PH. Co Reg No 1536540 Tel: (44) (0)20 7528 4000 Fax: (44) (0)20 7528 4500 http://www.jltgroup.com Lloyd's Broker. Regulated by the General Insurance Standards Council

Greetings, I'm working on image classification and for that I want to use the spectral slope as a feature for my classifier. For this I would prefer to calculate this feature using R, so far I've read my image and converted it's RGB representation into HSL. The spectral slope is computed over the Luminance component, so at the moment what I have is a NxN matrix of Luminance values.

The code below create an nxn upper triangular matrix of one's. I'm stuck on finding a more efficient vectorized way - Thanks. --Dale n <- 9 data <- matrix(data=NA, nrow=n, ncol=n) data for (i in 1:n) { data[,i] <- c(rep(1,i), rep(0,n-i)) } data

Dear Rusers, Trying to reduce my for loops addiction, could somebody tell me if there are ways to simplify (and perhaps accelerate ?) the following line for (i in 1:N) for (j in 1:N) m[i,j] = b[i]-b[j]; (where m is a NxN matrix and b a vector of length N) Thanks for any hint.

Hi, I tried looking through google search on whether there's a way to computer the median for each row of a nxn matrix and return the medians for each row for further computation. And also if the number of columns in the matrix are even, how could I specify which median to use? Thank you very much! -- Edward Chen [[alternative HTML version deleted]]

Is there a function or an easier way to computer geometric means of each rows in a nxn matrix and spit out in an 1xn matrix ? -- Edward Chen [[alternative HTML version deleted]]

Hi all, Here is my problem: I have 3 matrices , A, B, C. Each is an nXn matrix. I need to create matrix D such that : D[i,j]= (A[i,j]+B[i,j]+C[i,j])/3. Being a newbie this is proving to be a challenge. Any ideas on how best to accomplish this? Thanks! Anjan -- ============================= anjan purkayastha, phd bioinformatics analyst whitehead institute for biomedical research nine cambridge

Hi Just a simple question really. I?ve got these large 2d matrices that I?d like to inspect, but not from start to finish. The head() command is convenient when columns are few. For large nxn matrices, however, head() and head.matrix() are still cumbersome. Is there a simple way of viewing both the columnwise and rowwise heads of a matrix? cheers, Bruce -- View this message in context:

Dear All, I am struggling with the following problem: I am given a NxN symmetric matrix P ( P[i,i]=0, i=1...N and P[i,j]>0 for i!=j) which stands for the relative distances of N points. I would like use it to get the coordinates of the N points in a 2D plane. Of course, the solution is not unique (given one solution, I can translate or rotate all the points by the same amount and generate

Hello everyone I hope Im not bothering you all again. I have just begun to use R and so Im not yet familiarized with it.. I ve got an assignment which consists in calculating the area of a circle given a certain radius and center using the monte carlo method, which means that I have to plot a circle given its parameters. Limit the area inside it...with as many sample points as possible...and