Displaying 20 results from an estimated 30000 matches similar to: "Replacing string in matrix with zero"
2000 Feb 14
2
Error in the inverse of a diagonal matrix?
I?m new to R so maybe this issue has been asked before and I still could not read the complete set of past messages sent to the list.
I found a weird behabiour that I will explain with a simple example. Lets consider the following block of commands:
> x <- diag(c(1,4,10))
> x
[,1] [,2] [,3]
[1,] 1 0 0
[2,] 0 4 0
[3,] 0 0 10
> invx <- x^-1
> invx
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.,
2006 Oct 03
4
how ot replace the diagonal of a matrix
Dear useRs,
Trying to replace the diagonal of a matrix is not working for me. I
want a matrix with .6 on the diag and .4 elsewhere. The following
code looks like it should work--when I lookk at mps and idx they look
how I want them too--but it only replaces the first element, not each
element on the diagonal.
mps <- matrix(rep(.4, 3*3), nrow=n, byrow=TRUE)
idx <- diag(3)
mps
idx
mps[idx]
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
2006 Feb 05
3
reading in a tricky computer program output
Hi R user
I need to read in some values from a computer program output.
I can't change the output format because the developer of the program
doesn't allow to change the format of output.
There are two formats.
First one looks like this
if I have 10 variables,
------------------------------------------------------------------------------------------------------
[ 1]
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
2013 Apr 19
3
extracting the diagonal of an inverse matrix
Dear R-users,
I would like to know whether there is a way to extract a diagonal of an inverse matrix without computing the inverse of the matrix itself. The size of my matrices are really huge and, also using sparse matrix, computing the inverse leads to storage problems and low speed.
In other words, given a square matrix A, I aim to know diag(B), where B=solve(A), without computing solve(A).
2008 Apr 12
3
Matrix Indexing
Hi
Does anyone know how I might pick out diagonal elements of a matrix using a
vector?
If I create a matrix a:
a <- matrix(c(1:16), 4, byrow=TRUE)
and I want to pick out the elements (1,1),(2,2),(3,3), or another arbitrary
diagonal (upper or lower), is there any way I can use a vector to do this?
So if I want a diagonal of size 3, I could create a vector like x <- c(0:2)
and then pick
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
2009 Mar 11
3
Matrix Construction; Subdiagonal
I'm trying to enter a vector into the subdiagonal of a matrix but
cannot find a command in R which corresponds to the MatLab version of
diag(vec, k), where vec = the vector of interest, and k = the diagonal
(k=0 for the diagonal; k=-1 for the subdiagonal; k=1 for
superdiagonal, etc.)
Is there an equivalent command in R?
I'm looking for something like this:
vec = seq(1, 5, 1)
2009 Aug 26
1
Problem with standard generic methods in Matrix package
I have posted this message on r-lang, but it is perhaps more appropriate
on r-devel:
---
Hello,
I'm puzzled by a problem with call to diag(), rowSums(), rownames() on
objects of class "dgtMatrix", created by sparseMatrix() or spMatrix().
I use Matrix 0.999375-30.
The weird thing is that I don't encounter any problem when I use this
functions on the R prompt, or
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?
-------------------------------------------
2007 Oct 23
1
create diagonal matrix within a for cycle
? stato filtrato un testo allegato il cui set di caratteri non era
indicato...
Nome: non disponibile
Url: https://stat.ethz.ch/pipermail/r-help/attachments/20071023/b860b22b/attachment.pl
2008 Nov 21
2
Extracting diagonal matrix
Dear All,
I have a correlation matrix of size 100 x 100 and would like to extract the diagonal matrix from it. I have used the for loop to store tha correlation values of the diagonal matrix. Is there a 'R way' of doing this?
Thanks in advance.
Kind regards,
Ezhil
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
3
reordering of matrix rows to maximize the sum of the diagonal
Hi r-help community,
This question isn't so much a syntax/coding one, but here goes:
Let's say I have matrix of arbitrary dimensions and I'd like to
reorder the rows in such a way that I could maximize the sum of the
entries along the diagonal.
For example, for this 3x3 matrix:
[,1] [,2] [,3]
[1,] 3 4 13
[2,] 9 1 2
[3,] 2 11 1
rearranging the rows
2011 Dec 15
2
Data Manipulation - make diagonal matrix of each element of a matrix
Dear R list,
I have the following data:
set.seed(1)
n <- 5 # number of subjects
tt <- 3 # number of repeated observation per subject
numco <- 2 # number of covariates
x <- matrix(round(rnorm(n*numco),2), ncol=numco) # the actual covariates
x
> x
[,1] [,2]
[1,] -0.63 -0.82
[2,] 0.18 0.49
[3,] -0.84 0.74
[4,] 1.60 0.58
[5,] 0.33 -0.31
I need to form a matrix
2005 Jan 03
2
Memory Efficient Methods for Building Matrix
Dear List:
I am having to build a block-diagonal matrix (vl) and am currently using
the following code.
I<-diag(sample.size)
vl<-kronecker(I,vl.mat)
This code works fine, but for large N, it is a huge memory hog. Is there
a more efficient method for constructing vl?
Thanks,
Harold
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2007 Aug 22
3
rectify a program of seasonal dummies matrix
Hi friends,
I would like to construct a matrix of seasonal dummies with number of rows (observations)=100. such matrix is written as follows:[1 0 0 0;0 1 0 0;0 0 1 0;0 0 0 1;1 0 0 0;0 1 0 0;0 0 1 0;0 0 0 1;etc...] . I wrote the following program:
T=100
br=matrix(0,T,4)
{
for (i in 1:T)
for (j in 1:4)
if i==j
br[i,j]=1
if else (abs(i-j)%%4==0
br[i,j]=1
else
br[i,j]=0
}
z<-br
z
but
2006 Sep 26
2
about the determinant of a symmetric compound matrix
Dear R users,
even if this question is not related to an issue about R, probably some of you will be able to help me.
I have a square matrix of dimension k by k with alpha on the diagonal and beta everywhee else.
This symmetric matrix is called symmetric compound matrix and has the form
a( I + cJ),
where
I is the k by k identity matrix
J is the k by k matrix of all ones
a = alpha - beta
c =