Displaying 20 results from an estimated 400 matches similar to: "Ordering every row of a matrix while ignoring off diagonal elements"
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
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
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 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
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
2011 Jul 19
2
Taking all "complete" diagonals of a matrix
Hi R-Help!
I am trying to find a nicer way of extracting all the "complete" diagonals
of a matrix. I am working with very large matrices that have many more rows
than columns. I want to be able to extract each of the diagonals that are
as long as the number of columns in the matrix. I have written a rather
ugly function that presently does the job. It illustrates what I am trying
to
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
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
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
2007 Jul 26
0
Diagonal Submatrices Extraction
Yes you are right ... an example is mandatory.
So ... I have a matrix of 0 with just a single 1 per row and per column
I need to extract all maximal 'diagonal' submatrices
Let's say I have the following matrix
A B C D E
a 0 1 0 0 0
b 1 0 0 0 0
c 0 0 1 0 0
d 0 0 0 1 0
e 0 0 0 0 1
well I would like to get, for this example, the two following submatrices
A B C D E
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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indicato...
Nome: non disponibile
Url: https://stat.ethz.ch/pipermail/r-help/attachments/20080226/43b3a38b/attachment.pl
2007 Oct 10
3
as.dist with diagonal unequal zero
Hello and sorry that I still haven?t found a solution for my problem.
I need to extract the lower and upper triangle from a square matrix
including the diagonal. This diagonal is not zero in that special case.
I tried with as.dist
w<-as.dist(w, diag = TRUE)
> w
1 2 3 4 5
1 0
2 2 0
3 3 8 0
4 4 9 14 0
5 5 10 15 20 0
but found no way to keep the diagonal that is in the
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
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
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
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.,
2008 Jul 10
1
problems with rq.fit.sfn
Dear all,
I am running a quantile estimation with Sparse matrix and when I run
the procedure rq.fit.sfn I receive the following warning: tiny
diagonals replaced with Inf when calling blkfct.
Does anyone knows exactly what does it mean? What's this kind of
error? Should I get worried about this message?
The matrix I use is a full rank matrix (and indeed I do not have any
message about
2004 Jun 25
1
text, pos suggestion
suggestion: could the R team please add positions 5 through 8 for the
arg parameter in text(), which would select the diagonals (northeast,
southeast, southwest, northwest)?
sincerely, /ivo welch
PS: thanks for all the earlier circle help. knowing some of the
predispositions of the R developers, I probably should not suggest
adding to the documentation
> ?circle
please see