similar to: Array indexing

Displaying 20 results from an estimated 5000 matches similar to: "Array indexing"

1999 Mar 11
3
R and kron
I note that the CRAN at .at land still refers to 0.63.2. Is this just a typo? I don't want to download a whole lot only to find I still have it! Does 0.63.3 live elsewhere? And I note the new function kronecker - very useful but can it be applied to non-numerics as in factors, data frames etc preserving the class, levels and names? John
1999 Mar 11
3
R and kron
I note that the CRAN at .at land still refers to 0.63.2. Is this just a typo? I don't want to download a whole lot only to find I still have it! Does 0.63.3 live elsewhere? And I note the new function kronecker - very useful but can it be applied to non-numerics as in factors, data frames etc preserving the class, levels and names? John
2013 Feb 23
1
how to calculate left kronecker product?
For an application, I have formulas defined in terms of a left Kronecker product of matrices, A,B, meaning A \otimes_L B = {A * B[i,j]} -- matrix on the left multiplies each element on the right. The standard kronecker() function is the right Kronecker product, A \otimes_R B = {A[i,j] * B} -- matrix on the right multiplies each element on the left. The example below shows the result of
2005 Dec 08
1
kronecker(... , make.dimnames=TRUE)
Hi I'm using kronecker() with a matrix and a vector. I'm interested in the column names that kronecker() returns: > a <- matrix(1:9,3,3) > rownames(a) <- letters[1:3] > colnames(a) <- LETTERS[1:3] > b <- c(x=1,y=2) > kronecker(a,b,make.dimnames=TRUE) A: B: C: a:x 1 4 7 a:y 2 8 14 b:x 2 5 8 b:y 4 10 16 c:x 3 6 9 c:y 6 12 18 > The
2010 Nov 25
1
Request: kronecker to get a sep= argument
kronecker, with make.dimnames=TRUE uses a hardwired sep=":" in the line tmp <- outer(dnx[[i]], dny[[i]], FUN = "paste", sep = ":") For an application in which dimnames arise from an n-way array, where different dimensions have different roles, and I would like to be able to use kronecker in the form kronecker(A, B, make.dimnames=TRUE,
2012 Feb 09
1
Row-wise kronecker product with Matrix package
I'm trying to calculate the row-wise kronecker product A \Box B of two sparse matrices A and B, and am struggling to find a quick way to do this that takes advantage of sparseness. I thought a good idea would be to use "rep" to construct 2 matrices of the same dimension of the end product, and multiply these two together: library(Matrix) A<-Matrix(c(1,0,0,0,0,1,2,0), 2, 4)
2004 Jul 01
5
Zultys 4x4 or 4x5 ip phones?
Does anyone on-list use the Zultys 4x4 or 4x5 ip phones? I'd like to hear some opinion before I buy a few. I'm especially interested in the PSTN interface on the 4x5. Does it relay to * for VM when an incomming call is not answered by the phone? Thanks, Michael -- Michael Graves mgraves@pixelpower.com Sr. Product Specialist
2012 Jun 09
2
Matrix package loading problem "Error : object ‘kronecker’ is not exported by 'namespace:methods'"
Hi R users all , I have a clean install of R-2.15.0 in a win32 machine and a problem loading Matrix 1.0-6 that looks like this: > library(Matrix) Loading required package: lattice Error : object ?kronecker? is not exported by 'namespace:methods' Error: package/namespace load failed for ?Matrix? > I understand that kronecker() now has an S4 generic in package methods. Is that a
2005 Oct 13
3
Help with Matrix package
Hello all, A colleague at work set me the challenge to convert some MATLAB code into R, to see which is faster. We'd seen that benchmark comparing MATLAB 6.5 to R1.90 (and others), and so I thought that I should be able to get roughly comparable speeds. The code has lots of multiplications of matrixes, transposes, and MATLAB's "repmat". I did the code conversion, and R was about
2009 Feb 23
1
trade-off between speed and storage in matrix multiplications
Dear R-users, I coded two equivalent ways to perform (in a simplified version) some matrix multiplications I would like to use in a more general framework. In the first case I used Kronecker product and vectorization of a certain matrix. This approach takes less time, but, as you may guess, I run out of memory when dimensions are large. In the second approach, I profited of sparseness and
2011 Sep 27
1
array extraction
hello everyone. Look at the following R idiom: a <- array(1:30,c(3,5,2)) M <- (matrix(1:15,c(3,5)) %% 4) < 2 a[M,] <- 0 Now, I think that "a[M,]" has an unambiguous meaning (to a human). However, the last line doesn't work as desired, but I expected it to...and it recently took me an indecent amount of time to debug an analogous case. Just to be explicit, I would
2009 May 30
1
Spatiotemporal correlation function
Hi, I'm trying to compute  the spatiotemporal correlation matrix by using Delta Kronecker products of spatial and temporal correlation matrix  in R, but didn't find any delta Kronecker's operator in R. The operators in matrix such as multiplication, addition, eigen values/vector and etc is easily to find and used. Could someone help me, please? Cheers. Firdaus
2012 Nov 30
1
Fw: quantreg installation and conflicts with R 2.15.2
Just noticed that I get a similar error about object 'kronecker' in "Matrix" package when trying to load "lme4". So this is a more pervasive problem. Brian Brian S. Cade, PhD U. S. Geological Survey Fort Collins Science Center 2150 Centre Ave., Bldg. C Fort Collins, CO 80526-8818 email: brian_cade@usgs.gov tel: 970 226-9326 ----- Forwarded by Brian S
2011 Jun 05
2
kronecker sum
Dear All, Could someone please suggest how to find the Kronecker sum of two 2x2 matrices, i.e. given two matrices: -A A a -a and -B B b -b I need: -A-B A B 0 a -a-B 0 B b 0 -A-b A 0 b a -a-b Many thanks, Lara [[alternative HTML version deleted]]
2012 Nov 30
1
quantreg installation and conflicts with R 2.15.2
I recently lost the partitions on my hard drive (second time in 6 months) so I had to have our IT folks image all my files over to a new drive. I completely reinstalled R (now 2.15.2) and all my libraries to my computer (Dell Latitude running Windows 7). A few of my previous workspaces (created with R 2.14.1) can't be restored, reporting an error similar to the one I get when I try to
2010 Jan 07
1
faster GLS code
Dear helpers, I wrote a code which estimates a multi-equation model with generalized least squares (GLS). I can use GLS because I know the covariance matrix of the residuals a priori. However, it is a bit slow and I wonder if anybody would be able to point out a way to make it faster (it is part of a bigger code and needs to run several times). Any suggestion would be greatly appreciated. Carlo
2008 Nov 12
2
Outer, kronecker, etc.
`outer` (and related functions like kronecker) require that their functional argument operate elementwise on arrays. This means for example that outer( 1:2, 3:4, list) or outer(1:2,3:4,function(a,b){1}) gives an error. Is there a version of `outer`/`kronecker`/etc. that takes arbitrary functions and does its own elementwise mapping? In the first example above, I'd expect the
1999 Mar 18
2
e1071 and netpbm
Having compiled and successfully installed e1071 on a previous machine (and run under 0.62.4) I want to compile it on a new machine to run under 0.63.3 but the loader can't find netpbm - both machined are RH5.2 Linux installations. I have some quite old netpbm's on a CD but none more recent and I certainly didn't install them on my old machine. I can't locate or rpm -q or rpm
1999 Mar 18
2
e1071 and netpbm
Having compiled and successfully installed e1071 on a previous machine (and run under 0.62.4) I want to compile it on a new machine to run under 0.63.3 but the loader can't find netpbm - both machined are RH5.2 Linux installations. I have some quite old netpbm's on a CD but none more recent and I certainly didn't install them on my old machine. I can't locate or rpm -q or rpm
2005 Jul 13
2
Kronecker matrix product
Hi I want to write a little function that takes a matrix X of size m-by-n, and a list L of length "m", whose elements are matrices all of which have the same number of columns but possibly a different number of rows. I then want to get a sort of dumbed-down kronecker product in which X[i,j] is replaced by X[i,j]*L[[j]] where L[[j]] is the j-th of the "m" matrices. For