similar to: Split matrix into square submatices

Displaying 20 results from an estimated 4000 matches similar to: "Split matrix into square submatices"

2015 Oct 29
2
Extraer elementos diagonales de submatrices
El código que me olvide pegar input m <- structure(c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 5, 5, 5), .Dim = c(10L, 5L)) m ## output output <- c(1:3, 1:5, 1:2) output nfilas <- nrow(m) while(nfilas > 0) { diagonal <- diag(m)
2015 Oct 28
3
Extraer elementos diagonales de submatrices
Estimado Javier, Gracias por tu mensaje. No, lo unico que requiero es la lista de números (i1, 2, 3, 1, 2, 3, 4, 5, 1, 2). Saludos cordiales, Jorge.- 2015-10-28 14:35 GMT-05:00 Javier Rubén Marcuzzi < javier.ruben.marcuzzi en gmail.com>: > Estimado Jorge I Velez > > > > No comprendo un punto, dices que deseas construir sub matrices y extraer > elementos de sub
2015 Oct 28
2
Extraer elementos diagonales de submatrices
Buenos dias a todos, Quisiera extraer algunas entradas de una matrix "m" teniendo en cuenta algunas restricciones. El siguiente ejemplo ilustra la situacion: ## input m <- structure(c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 5, 5, 5), .Dim = c(10L, 5L)) m ## output output <-
2012 Oct 22
4
Help with applying a function to all possible 2x2 submatrices
Hi all, I'm working with a large data set (on the order of 300X300) and trying to apply a function which compares the elements of all possible 2x2 submatrices. There are rc(r-1)(c-1) such submatrices, so obviously the naive method of looping through the rows and columns is computationally unfeasible for my data set: for(i in 1:(nrow(data)-1)) { for(j in (i+1):nrow(data)) { for (m
2012 Aug 23
1
Why was my R process killed spontaneously?
I tried to use gpuCor function in the gputools package of R to calcuate the pairwise correlations of a matrix of 40,000 columns. Becuase there would be memory issues if I use the whole matrix at a time, I splitted the matrix into submatrix of 10,000 columns and then calculate the pairwise correlation of different submatrices. There are altogether 4 submatrices, so I need to calculate the pearson
2004 Sep 15
2
efficient submatrix extraction
Hi, I have a matrix of say 1024x1024 and I want to look at it in chunks. That is I'd like to divide into a series of submatrices of order 2x2. | 1 2 3 4 5 6 7 8 ... | | 1 2 3 4 5 6 7 8 ... | | 1 2 3 4 5 6 7 8 ... | | 1 2 3 4 5 6 7 8 ... | ... So the first submatrix would be | 1 2 | | 1 2 | the second one would be | 3 4 | | 3 4 | and so on. That is I want the matrix to be evenly divided
2006 Jun 19
2
Nested variance-covariance matrix in Multilevel model
Dear R community, I have trouble implementing a nested variance-covariance matrix in the lme function. The model has two fixed effects called End and logpgc, the response variable is the logarithm to base 2 of Intensity ( log2(Intensity) ) and the random effects are called Probe and ProbeNo. The model has the following nesting structure: A Pixel is nested within the ProbeNo,the ProbeNo is
2012 Jul 31
1
ways of getting around allocMatrix limit?
I need to multiply to very large, nonsparse matrices, and so get the error "allocMatrix: too many elements specified". Is there a way to set the limit for allocMatrix? In my case, the two matrices, A and B, are nxm and mxp where m is small, so I could subdivide each into blocks of submatrices A=rbind(A1,A2,...) and B=cbind(B1,B2,...) then multiply each pair of submatrices, but I was
2012 Oct 30
2
Put submatrices in an array
Dear R users, I have a Hadamard matrix 16x15 and i want to put 16x5 submatrices in an array put i have an error. > A1<-matrix(c(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 1,0,1,0,1,0,1,0,1,0,1,0,1,0,1, + 0,1,1,0,0,1,1,0,0,1,1,0,0,1,1, + 1,1,0,0,1,1,0,0,1,1,0,0,1,1,0, + 0,0,0,1,1,1,1,0,0,0,0,1,1,1,1, + 1,0,1,1,0,1,0,0,1,0,1,1,0,1,0, + 0,1,1,1,1,0,0,0,0,1,1,1,1,0,0, + 1,1,0,1,0,0,1,0,1,1,0,1,0,0,1, +
2011 Apr 27
2
sub-matrix block size
Dear Rxperts Below is a small vector of values of zeros and non-zeros... was wondering if there is an efficient way to get the block sizes of submatrices of a big matrix similar to the one shown below? diagonal elements can be zero too. Rows with only a diagonal element may be considered as a unit block size. c(1,0,0,0,0,0,0,0,0,0,0, 1,1,0,0,0,0,0,0,0,0,0, 0,0,1,0,0,0,0,0,0,0,0,
2002 Feb 01
3
matrix with ncol=1
Hello list, I try to optimize some R code and it turns out that the function as.matrix takes a lot of time in my code. There is only one reason why I need as.matrix: My code should work for matrices with ncol=p and p should be allowed to be 1 or larger. Now I have a matrix x with dim(x)=(n,p), and I need to work with the submatrix y <-x[gv,], (gv a vector of n logicals) and to calculate
2005 Apr 26
1
Index matrix to pick elements from 3-dimensional matrix
Hi all Suppose I have a dim=c(2,2,3) matrix A, say: A[,,1]= a b c d A[,,2]= e f g h A[,,3]= i j k l Suppose that I want to create a 2x2 matrix X, which picks elements from the above-mentioned submatrices according to an index matrix J referring to the "depth" dimension: J= 1 3 2 3 In other words, I want X to be X= a j g l since the matrix J says that the (1,1)-element should be
1998 Apr 09
1
0-extent matrices?
Is there a good reason not to allow matrix extents to be zero? I have been writing a function which fits glms under certain linear constraints. I fit the model with a reduced set of variables and then transform back to the original set. This involves operating on submatrices of the covariance matrix and subsets of the coefficients. Sometimes these subsets are empty. A zero-length subset of the
2007 Apr 25
1
for loops
Hello everybody I'm very new at using R so probably this is a very stupid question. I have a matrix of "p" columns and I have to calculate for each of them the "two sample t-statistic" and p-value and to save the results into two different vectors. I have divided my matrix into two submatrices: submatrix A containing the first "n1" rows (p columns) and submatrix B
2009 Nov 22
1
"Over-coloring" facets on persp() plot
Dear R Community: Recently, I have managed to plot some really useful graphs of my research data using persp(). I have even figured out how to overplot rectangular regions (corresponding to submatrices) with a different color. This is accomplished by using par(new=T). I am now searching for a way to "highlight" a set of (possibly non-contiguous) facets with a specific color,
2010 Jun 04
1
parttioning a matrix corresponding to different levels of y
Sir, I have a problem regarding partitioning a matrix.I state my problem as follows: I have a y vector of length say 1000.Variable y has 4 levels say 0,1,2.Corresponding to each y(response), I have a x-vector(explanatory) as a row of X matrix.Now, I want to partition the X matrix into 3 submatrices say x1,x2,x3 corresponding to each level of y.Is there any function to do this in R or how can I
2011 Aug 02
1
Functions for Sum of determinants of ranges of matrix subsets
Dear R-help list, Pls I have this problem. Suppose I have a matrix of size nxn say, generated as follows   z<-matrix(rnorm(n*n,0,1),nrow=n)   I want to write a function such that for i in 1:n, I will remove the rows and columns corresponding to i (so, will be left with n-1*n-1 submatrix in each cases). Now I need the sum of the determinant of each of this submatrices. As an example, if n=3, it
2004 Jan 26
3
write.table file="file.txt" help
Hi all, I have a R script that creates several input files for an analysis program. It loops through the matrix read into R and picks out submatrices and then creates a separate output file for each submatrix. The loop works great, but I am having trouble getting all the separate output files written. The line I have is: write.table(ch1d,
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
2010 Apr 09
0
Fox's algorithm?
I'm interested in a serial implementation of fox's algorithm for memory management reasons. Does anybody know if there is anything available in R or C libraries? [eg A %*% B is too big to allocate memory for. I really want the values written to disk, so I was thinking that it would be easiest to use something like Fox's algorithm to load submatrices/blocks of A and B iteratively, do