similar to: Taking all "complete" diagonals of a matrix

Displaying 20 results from an estimated 10000 matches similar to: "Taking all "complete" diagonals of a matrix"

2013 Jan 23
2
setting off-diagonals to zero
The following 1460 x 1460 matrix can be throught of as 16 distinct 365 x 365 matrices. I'm trying to set off-diaganol terms in the 16 sub-matrices with indices more than +/- 5 (days) from each other to zero using some for loops. This works well for some, but not all, of the for loops. The R code I"m using follows. For some reason the third loop below zero's-out everything in the
2008 Feb 26
2
Summing up diagonals w/o for-loop
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2005 Feb 04
4
Building a Matrix
Dear List: I am having some difficulty constructing a matrix that must take a specific form. The matrix must be have a lower block of non-zero values and the rest must all be zero. For example, if I am building an n X n matrix, then the first n/2 rows need to be zero and the first n/2 columns must remain as zero with all other elements having a non-zero value that I specify. For example, assume
2007 Jun 20
1
How to extract diagonals
Hello, I am using Mac OS X on a power book and R 2.5.0 I try to extract a diagonal from a dissimilarity matrix made with dsvdis, with this code: diag(DiTestRR) But I get this error message: Fehler in array(0, c(n, p)) : 'dim' spezifiziert ein zu großes Array english: Error in array(0, c(n, p)) : 'dim' specifies a too big array. Is there a limit to extract diagonals? I
2011 Feb 25
1
Accessing sub diagonals / spdiag in R ?
Hello, I'm attempting to access a specific number of sub diagonals in a MATRIX and have been accustomed to using spdiags in MATLAB or Octave. I've got a solution pieced together using for loops and it works though isn't vectorized and liable to run very slow for large matrices. As an example: A = 1 2 3 4 5 9 8 7 6 5 4 5 6 7 8 5 4 3 2 1 8 7 6 0 1 The subdiagonals are: 9,5,3,0 4,4,6
2001 May 19
2
calculations on diagonals of a matrix
Given an nxm matrix A I want to compute the nxm matrix B whose ij-th element is the sum of the elements of A lying on the diagonal that ends with element ij, i.e., b_ij = a_ij + a_(i-1)(j-1) + a_(i-2)(j-2) + ... In APL (which I no longer use), I would use the 'rotate' operator to derive an array whose columns are diagonals of the given array and then cumulate down columns. Is
2004 Oct 13
2
diagonal matrix construction
Hi, I have worked long and hard and looked in the manuals and am having a hard time constructing a diagonal matrix. I can get the diagonals out of a matrix but can't construct the matrix with just the diagonals. I have been on the web site and manuals and I think that it says to use: dsj <- diag (three = 1, nrow, ncol = 7) three is the name of my matrix and
2011 Apr 04
1
Ordering every row of a matrix while ignoring off diagonal elements
Sorry if this is a stupid question but I've been stuck on how to code so that I can order rows of a matrix without paying attention to the diagonal elements. Say, for example, I have a matrix d: > d [,1] [,2] [,3] [,4] [1,] 0.000000 2.384158 2.0065682 2.2998856 [2,] 2.384158 0.000000 1.4599928 2.4333213 [3,] 2.006568 1.459993 0.0000000 0.9733285 [4,] 2.299886
2012 Apr 12
3
writing spdiags function for R
Dear R-list, I am in the process of translating a long function written in Matlab into R (mainly because I am a big of fan of R, and folks will not have to pay to use it :). In the translation of this function I got stack because they use spdiags, which, as far as I can tell it is not available in R. I have explored the Matrix package, from which I borrowed some of the functions (e.g.,
2011 Dec 08
2
Relationship between covariance and inverse covariance matrices
Hi, I've been trying to figure out a special set of covariance matrices that causes some symmetric zero elements in the inverse covariance matrix but am having trouble figuring out if that is possible. Say, for example, matrix a is a 4x4 covariance matrix with equal variance and zero covariance elements, i.e. [,1] [,2] [,3] [,4] [1,] 4 0 0 0 [2,] 0 4
2009 Aug 24
1
Filling matrix secondary diagonal
Hi, how do i fill the secondary diagonals of a matrix? Is there an funktion like the "diag" funktion in matlab, where i can specify the diagonal i?d like to fill? -- View this message in context: http://www.nabble.com/Filling-matrix-secondary-diagonal-tp25121745p25121745.html Sent from the R help mailing list archive at Nabble.com.
2010 Apr 23
2
Matrix diagonal help
Hi Suppose I have a matrix (cohort are rows and years are columns) [2000] [2001] [2002] [2003] [C1] 0.01 0.03 0.02 0.09 [C2] 0.06 0.05 0.07 0.11 [C3] 0.1 0.5 0.4 0.98 [C4] 0.7 0.6 0.2 0.77 I want to extracts the diagonals to get a matrix which looks like this (C1 becomes C2 in 2002, C2 becomes C3 in 2003
2024 Dec 04
3
Undocumented behaviour of diag when replacing the diagonal of a matrix?
Dear list, is anyone aware of the following behavious of diag when used to replace diagonals (plural!) of a matrix? Small example: The following is documented and clearly to be expected: A <- matrix(0, nrow = 5, ncol = 5) diag(A) <- 1; A BUT, what about the following? When executing the code of `diag<-` line by line, it throws errors. So why does it work? diag(A[-1, ]) <- 2; A
2010 Mar 01
1
function odiag(): assigning values to off-diagonal
hi I'm trying to use the function odiag(x) for matrix calculations. I would like to assign new values to an off-diagonal in a matrix. When I use the diag (x) function I could write something like p<-matrix(seq(1:12),ncol=4) p.new<-matrix(rep(0,12),ncol=4) diag(p.new)<-diag(p) p.new But this won't work with odiag. How can I turn odiag (x) into something like diag (x) in order
2010 Oct 07
1
Lattice: Histogram in splom diagonals
Dear list, I want to plot several variables with splom and in the main diagonal, instead of the variable names, I'd like to plot an histogram of corresponding variables. Searching I did not find the correct syntax, only some tips in an old post in the list, but this comments help to plot only density lines instead of histograms. I had some code, but it fails to plot (I've commented the
2009 Nov 08
2
influence.measures(stats): hatvalues(model, ...)
Hello: I am trying to understand the method 'hatvalues(...)', which returns something similar to the diagonals of the plain vanilla hat matrix [X(X'X)^(-1)X'], but not quite.  A Fortran programmer I am not, but tracing through the code it looks like perhaps some sort of correction based on the notion of 'leave-one-out' variance is being applied. Whatever the
2011 Jan 20
2
splitting a square symmetric matrix
So many matrices are square symmetrical (i.e. variance-covariance matrices), is there any way to get R to split the matrix on its diagonal and just return one diagonal? So if I have mat<-matrix(c(1,4,3,4,1,2,3,2,1), nrow = 3, ncol=3, byrow=TRUE) is there anyway to get the lower right diagonal instead of the entire symmetric matrix? -------------------------------------------
2005 Jan 20
3
Constructing Matrices
Dear List: I am working to construct a matrix of a particular form. For the most part, developing the matrix is simple and is built as follows: vl.mat<-matrix(c(0,0,0,0,0,64,0,0,0,0,64,0,0,0,0,64),nc=4) Now to expand this matrix to be block-diagonal, I do the following: sample.size <- 100 # number of individual students I<- diag(sample.size) bd.mat<-kronecker(I,vl.mat) This
2010 Oct 21
4
how do I make a correlation matrix positive definite?
Hi, If a matrix is not positive definite, make.positive.definite() function in corpcor library finds the nearest positive definite matrix by the method proposed by Higham (1988). However, when I deal with correlation matrices whose diagonals have to be 1 by definition, how do I do it? The above-mentioned function seem to mess up the diagonal entries. [I haven't seen this complication, but
2010 Oct 11
1
running R script on linux server
Hi R-users, I have a problem running my R code on a Linux cluster. What I did was write a .pbs file to instruct the cluster on what to do and how: #!/bin/sh #PBS -m ae #PBS -M uqlcatta@uq.edu.au #PBS -A uq-CSER #PBS -N job1_lollo #PBS -l select=1:ncpus=1:NodeType=fast:mem=8GB #PBS -l walltime=999:00:00 cd $PBS_O_WORKDIR source /usr/share/modules/init/bash module