similar to: Subsetting a matrix without for-loop

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Dear R-users, I am going to try to be as clearer as possible, showing also an example. 1) I have a function (in my real case it's much more complex) 2) I use "optim" to minimize 3) I want to use as method L-BFGS-B for several reasons 4) I know I could use "trace=6" (in "control") in order to see "live" the procedure 5) I would like to see separately the

Dear R-users, I am working with some grid-search optimization for 13 values of an object function. At glance one may compute the object function for each possible combination of set of parameters, but in my case would not be feasible: taking for example 13 possible values for each parameters like, in logarithm scale, 10^seq(-3,3,.5) will lead to 13^13 combinations of results. As a second trial

Dear R-users, I couldn't find a function or some help in R-project web about the Generalized Singular Value Decomposition. In MatLab there is a simple function for this algebric issue (gsvd). Is there anything like that in R? And, if not, could you help me to apply this method in R? Thanks in advance, Giancarlo +++++ This mail has been sent through the MPI for Demographic Rese...{{dropped}}

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).

Dear R-users, within the rgl-package, I would have a question about the usage of persp3d in combination of rgl.viewpoint. I am not able to figure out how to let a 3D plot rotating around likewise the example in ?rgl.viewpoint. It seems that when I use persp3d(...) I see something on my screen, which is different from what I get when it's rotating. Is there any different behavior between

Dear R-users, I would like to place two 3D plots side-by-side in a rgl-setting. It would nice to have something like "par(mfrow=c(1,2))" for basic plots, or an array framework for wireframe(lattice) (see example below). I only managed to overlap two persp3d plots. My final idea would be to animate both surfaces using play3d(rgl). Thanks in advance for any help. Best, Carlo Giovanni

Dear R-friends, I use optim(par=c(mystartingpoints), fn=myloglikelihoodfunction, gr=NULL, method=c("L-BFGS-B"), ## I would like to do not use any bounds control=list(trace=6, ## just to see what it's going on maxit=c(20000)), ## to be sure the it doesn't stop reaching the max iterations

Hello, I'd like to draw a graphic using different color line segments to represent microarray data. It simply likes this: Data=cbind(c(1, 2, -1, 3, -2.2), c(1, 3, -1, -1.8, 4)) The first col No represents y'axis position (negative down and positive up). The second col No represents a length of segment (negative segment should be on left of y, and positive on right). Also the

I am using R 2.2.1 on a Windows 2000 PC. When I do a grid() after the boxplot it overprints the boxplot: > boxplot(count ~ spray, data = InsectSprays, col = "lightgray") > grid(nx=NA, ny=NULL) > if I try the panel.first > boxplot(count ~ spray, data = InsectSprays, col = "lightgray", + panel.first=grid(nx=NA, ny=NULL)) > I can see the grid flash

Dear R-user, I would like to apply spatial statistics on some historical data, in particular from 1850 to 1900 by registration district of England and Wales. I have searched in the R-archive, but unsuccessfully. Do you know whether R contains those shape files? Or where would be possible to download and use in R? Thanks in advance, Carlo Giovanni Camarda +++++ This mail has been sent through the

Dear R-users, I would a small problem saving a graph with postscript after using xyplot. Whereas in the R-screen the two lines are solid, once the image is saved as .eps file the second lines (blue in the following example) is dotted. Here there is a simple example. Thanks in advance for your help, Carlo Giovanni Camarda # creating data a1 <- sort(runif(10)) a2 <- sort(runif(10)) a3 <-

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Dear R-users, I would like to ask whether it's possible (for sure it would be), to plot each rows (or columns) in different graphs and in the same figure region without using the function "par" and then struggling around with "axes" and labels etc. Luckily, I would always have "rows + columns = even number" and the same "ylim". The next one could be a

Dear R-Users, without going into details I tried to prepare a simple example to show you where I would need help. In particular I prepare two examples-template for a study I'm conduction on discrete-time methods for survival analysis. Each of this example has two datasets which are basically equal, with the exception that in the former one has individual data and in the latter one aggregated

Dear R-Helpers, I have a matrix where the first column is known. The second column is the result of multiplying this first column with a constant "const". The third column is the result of multiplying the second column with "const"..... So far, I did it like this (as a simplified example): nr.of.columns <- 4 myconstant <- 27.5 mymatrix <- matrix(numeric(0), nrow=5,

Dear R-users, would it be a better way to construct the matrix below without using any for-loop or model.matrix? preferably with some matrix algebra? Thanks in advance, Carlo Giovanni Camarda ## dimensions m <- 3 n <- 4 mn <- m*n k <- m+n-1 ## with a for-loop X <- matrix(0, mn, k) for(i in 1:n){ wr <- 1:m+(i-1)*m wc <- rev(1:m+(i-1)) where <- cbind(wr,wc)

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Dear R-users, I'd like to plot a three-dimensional surface and at the meantime I'm using an array. I would like to have the values of my first matrix in the heights of the plot and the colors of the single facet taking into account the second matrix. I hope that the next code will help all of you to understand better my issue, Thanks in advance, Giancarlo ############################ ##

Dear R-users, I am searching to the "best" way to compute a series of n matrix multiplications between each matrix (mXm) in an array (mXmXn), and each column of a matrix (mXn). Please find below an example with four possible solutions. The first is a simple for-loop which one might avoid; the second solution employs the tensor product but then manually selects the right outcomes. The