similar to: Matrix transformation problem

I'm trying to create a new column in my data.frame where subjects are categorized depending on values on four other columns. In any other case I would just nest a few ifelse statements, however, in this case i have 4*6*2*3=144 combinations and i get weird 'context overflow' errors. So I wonder if there is a more efficient way of doing this. For illustrational purposes, let's say

Dear all, I have a population with three age-classes, at time t=0 the population is: n.zero <- c(1,0,0) I have a transition matrix A which denotes "fertility" and "survival": A <- matrix(c(0,1,5, 0.3,0,0, 0,0.5,0), ncol=3, byrow=TRUE) To obtain the population at t=1, I calculate: A %*% n.zero To obtain the population t=2, I calculate: A %*% (A %*% n.zero) ... and so

hi, I have some session data in a dataframe, where each session is recorded with a start and a stop date. Like this: session_start session_stop =================== 2009-01-03 2009-01-04 2009-01-01 2009-01-05 2009-01-02 2009-01-09 A session is at least one day long. Now I want a dataframe with 'active sessions' per date. Like this: date active_sessions ============= 2009-01-01 1

Hi R, I have a vector V1 of unknown length, say n. I need to convert this into a matrix C of row size=5, and accordingly the column should be updated. I tried with: C=as.matrix(V1,5,n/5) But it is not working...Could somebody help me on this? Thanks in advance... [[alternative HTML version deleted]]

Hi, A small (but annoying) problem with RMySQL library. When a connection is closed, it echoes 'TRUE' to the console. Like this: R> mysqlCloseConnection(con) [1] TRUE The real problem comes when I use RMySQL with Sweave, since the TRUE echo gets into my final Sweave document. Even when I explicitly state <<include=FALSE, echo=FALSE>>= in the header of the R code chunk.

I'm trying to typeset at simple crosstable with the Hmisc latex function. And I have two problems. 1. How do I make all columns the same width? The Latex function seems very unwilling to break the 'cgroup' labels and the factor level labels. Please have look at this screenshot that shows my problem: >> http://hem.passagen.se/stpe9096/table.png So, how can I make sure that the

Hi everybody, I would like to apply cor.test to a matrix with m rows and n columns and get the results in a list of matrices , one matrix for p.val, one for the statistic, one for the correlation and 2 for upper and lower confidence intervals, something analog with cor() applied to a matrix. I have done my own function to get a matrix of p.values and i suppose i can build similar functions for

Hi I have two processes which take with a certain probability (p1 and p2) x number of years to complete (age1 and age2). As soon as thge first process is completed, the second one begins. I want to calculate the time it takes for the both processes to be completed. I have the following script which gives me the answer, butI think there must be a more elegant way of doing the calculations

I'm trying to dynamically build variable names to use on a list. Let's say I have a list like this one: l <- list(V1_1=c(1,2,3), V1_2=c('One','Two','Three')) And I succesfully build my variable name like this: paste('l$', 'V1_1', sep='') Why can't I just run a mean call with the pasted variable name? mean(paste('l$',

Hi, I'm trying to create a distance matrix. And it works out somewhat ok. However, I suspect that there are some efficiency issues with my efforts. Plz have a look at this: donor <- matrix(c(3,1,2,3,3,1,4,3,5,1,3,2), ncol=4) receiver <- matrix(c(1,4,3,2,4,3,1,5,1,3,2,1,4,5,3,5,1,3,2,4,5,1,2,3,1,4,5,5,1,2,1,3,4,3,2,5,5,1,4,2,5,4,3,2), ncol=4) The above creates my two matrices. I have

Hallo, I'll need a matrix with n rows of the an identical vector. > h [1] 3 3 3 3 2 2 2 The nmatrix should look like this: > x<-rbind(h,h,h) > x [,1] [,2] [,3] [,4] [,5] [,6] [,7] h 3 3 3 3 2 2 2 h 3 3 3 3 2 2 2 h 3 3 3 3 2 2 2 but I need n rows which must be variable. Can anyone help me? thanks Andreas

II am translating some gauss code into R, and gauss has a matrix product function called the horizontal direct product (*~), which is some sort of variant on the Kronecker product. For example if x is 2x2 and y is 2x2 the horizontal direct product, z, of x and y is defined (in the Gauss manual) as: row 1 = x11*y11 x11*y12 x12*y11 x12*y12 row 2 = x21*y21 x21*y22 x22*y21 x22*y22 Or in R

Hallo >From a variable "x" that defines, say, four classes, I would like to define the matrix "mat" of dummy variables indicating the classes, i.e. x <- c(1,1,1,1,2,2,2,3,3,3,4,4) mat <- matrix(c(1,0,0,0, 1,0,0,0, 1,0,0,0, 1,0,0,0, 0,1,0,0, 0,1,0,0, 0,1,0,0, 0,0,1,0, 0,0,1,0, 0,0,1,0, 0,0,0,1, 0,0,0,1), ncol=4, byrow=T) Thank you for your help, Serguei

Dear, I am looking for the simplification of a formula to improve the calculation speed of my program. Therefore I want to simplify the following formula: H = sum{i=0..n-1 , [ sum {j=0..m-1 , sqrt ( (Ai - Bj)^2 + (Ci - Dj)^2) } ] } where: A, C = two vectors (with numerical data) of length n B, D = two vectors (with numerical data) of length m sqrt = square root Ai = element of A with index

Hi, I want to make the following array of numbers: -3 -3 -3 -3 -3 -3 -3 -2 -2 -2 -2 -2 -2 -2 ... 3 3 3 3 3 3 3 -3 -2 -1 0 1 2 3 -3 -2 -1 0 1 2 3 ... -3 -2 -1 0 1 2 3 (3 would be N, a painful example to type number). Here is my dirty attempt to do it, > N<-3 > > x<-c(-N:N) > > rj<-rbind(matrix(outer(matrix(1,1,2*N+1),x),nrow=1),rep(x,2*N+1)) > It

I need help regarding to the following problem: Consider this matrix: > M <- matrix(c(1,2, 4,3, 1, 2),3, 2, byrow=TRUE) > M [,1] [,2] [1,] 1 2 [2,] 4 3 [3,] 1 2 I would like to have a matrix which counts the identical rows and places the counts into its third column. I tried with ftable(): > as.data.frame(ftable(M[,1], M[,2])) Var1 Var2 Freq 1 1 2

Hi, I have matrix of bits and a target vector. Is there an efficient way to search the rows of the matrix for the target? I am interested in the first row index where target is found. Example: > source("lookup.R") [,1] [,2] [,3] [,4] [,5] [1,] 1 0 1 1 0 [2,] 1 1 0 1 0 [3,] 0 0 1 0 0 [4,] 1 0 0 1 1 [5,]

Hello, I am using R 1.9.1 on Windows 2000 SP4. I have the following problem: Say I have a matrix, >my.matrix [,1] [,2] [,3] [1,] "A" "B" "C" [2,] "D" "E" "F" [3,] "G" "H" "I" I would like to apply an operation to this matrix which returns a list my.list containing the

I'd like to remove duplicated rows within a matrix, with missing data being treated as wildcards. For example > x <- matrix((1:3), 5, 3) > x[4,2] = NA > x[3,3] = NA > x [,1] [,2] [,3] [1,] 1 3 2 [2,] 2 1 3 [3,] 3 2 NA [4,] 1 NA 2 [5,] 2 1 3 I would like to obtain [,1] [,2] [,3] [1,] 1 3 2 [2,] 2 1 3

Hi, I've set up a very simple R repository. Just a single source library. Everything works fine. I can install the package on my client using: install.packages(repos='http://www.myServer.se/myRepo/', pkgs='myLib', dep=TRUE) However, I want to protect the repo, so I use a .htaccess, placed directly under 'myRepo' on the server. I use 'Authentication Basic' and