similar to: compare and replace

Hello, #I have two matrices, eg.: y <- matrix( c(20, NA, NA, 45, 50, 19, 32, 101, 10, 22, NA, NA, 80, 49, 61, 190), ncol=4 ) x <- matrix( c(20, NA, NA, NA, 50, 19, 32, 101, 10, 22, NA, NA, 80, 49, 61, 190), ncol=4 ) #Whereas x contains all NA?s from y plus some additional NA?s. #I want to find the index of these additional NA?s. I think, there must be a very

Dear list, I'd like to use the function cut() on matrices, ie that when I apply it to a matrix, it would return a matrix of the same dimensions instead of a vector. I wonder if there is a better (more elegant) solution than matrix(cut(a, ...), ncol=ncol(a), nrow=nrow(a)) because I would like to use cut on both vectors and matrices and avoid testing whether a is a matrix. Thanks, Tamas

Hello fellow R users, I have a matrix computation that I imagine should be relatively easy to do, however I cannot figure out a nice way to do it. I have two matrices, for example mat1 <- matrix(c(1:5,rep(NA,5), 6:10), nrow=3, byrow=T) mat2 <- matrix(c(2:6, 6:10, rep(NA,5)), nrow=3, byrow=T) I'd like to compute the element-wise average for non-NA entries. Of course (mat1+mat2)/2

Dear R-users, I was wondering for the following: Let 'x' be a matrix and 'ind' and indicator matrix, i.e., x <- array(1:20, dim = c(4, 5)) ind <- array(c(1:3, 3:1), dim = c(3, 2)) I'd like to get (as a vector) the elements of 'x' which are not indexed by 'ind'. Since negative indices are not allowed in index matrices I thought of using something like:

Hi Everyone, I am running into a problem with matrices. I use R version 2.4.1 and an older version. The problem is this: m<-matrix(ncol=3,nrow=4) m[,1:3]<-runif(n=4) That does what I expect; it fills up the rows of the matrix with the data vector > m [,1] [,2] [,3] [1,] 0.2083071 0.2083071 0.2083071 [2,] 0.5865763 0.5865763 0.5865763 [3,] 0.7901782 0.7901782

Hi, Can anyone help to write a more elegant version of my code? I am sure this can be put into a loop but I am having trouble creating the objects b1,b2,b3,...,etc. b1 <- rigamma(50,1,1) theta1 <- rgamma(50,0.5,(1/b1)) sim1 <- rpois(50,theta1) b2 <- rigamma(50,1,1) theta2 <- rgamma(50,0.5,(1/b2)) sim2 <- rpois(50,theta2) b3 <- rigamma(50,1,1) theta3 <-

Hi, I want to make a data frame which contains the positions of some searched values in another data frame. Like: Dataframe 1: 1 2 3 4 1 2 3 4 2 3 4 1 2 3 4 2 4 1 2 3 2 3 4 1 Let's say I searched on "4", then Dataframe 2 should contain: x y 1 4 1 8 2 3 2 7 3 1 3 7 I have written a routine, but it seems to me that it isn't that perfect: x<- 0

I've been doing some consulting with students who seem to come to R from SAS. They are usually pre-occupied with do loops and it is tough to persuade them to trust R lists rather than keeping 100s of named matrices floating around. Often it happens that there is a list with lots of matrices or data frames in it and we need to "stack those together". I thought it would be a simple

Dear expeRts, I have two matrices A and B. They have the same number of columns but possibly different number of rows. I would like to compare each row of A with each row of B and check whether all entries in a row of A are less than or equal to all entries in a row of B. Here is a minimal working example: A <- rbind(matrix(1:4, ncol=2, byrow=TRUE), c(6, 2)) # (3, 2) matrix B <-

Dear list, I'm trying to replace NA-values with the preceding values in that column. This code works, but I am sure there is a more elegant way... df <- data.frame(id = c("A1", NA, NA, NA, "B1", NA, NA, "C1", NA, NA, NA, NA), value = c(1:12)) rn <- c(rownames(df[!is.na(df$id),]), nrow(df)+1) rn <-

Hi, Can any one please explain why the following code doesn't work? Or can anyone suggest an alternative. Suppose       x<-c(23,67,2,87,9,63,8,2,35,6,91,41,22,3)        mat<-0;        for(j in 1:length(x))        {              for(i in 1:p)                      mat[i,j]<-x[j]^i;        }    Actually I want to have a matrix with p columns such that each column will have the

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 have a dataframe called "tests" that contain "character expressions". These characters are rules that use data from within another dataframe. Is there any way within R I can access the rules in the dataframe called tests, and then "evaluate" these "rules"? #An example may better explain what I am trying to accomplish: tests <-

There was a BioConductor thread today where the poster wanted to find pairwise difference between columns of a matrix. I suggested the slow solution below, hoping that someone might suggest a faster and/or more elegant solution, but no other response. I tried unsuccessfully with the apply() family. Searching the mailing list was not very fruitful either. The closest I got to was a cryptic chunk

Hi. Can anyone suggest a simple way to re-sort in R a list of vectors of the following form? input $"1" a b c 1 2 3 $"2" a b c 4 5 6 Output should be something like: "a" "1" 1 "2" 4 "b" "1" 2 "2" 5 "c" "1" 3 "2" 6 I've been futzing with mapply(), outer(), split(), rbind()

Hello everybody. I am trying to reproduce a particular matrix in an elegant way. If I have jj1 <- structure(c(1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2, 3,1,2,3,1,2,3,1,2,3,2,3,1,2,3,1,2,3,1,2,3, 1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,3,1,2,3,1, 2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1, 2),.Dim = as.integer(c(9,9))) [ image(jj1) is good here ] then I can get this with

Hi, thank you for taking the time and reading my question. My question is twofold: 1. I have several matrices with variables and one matrix with water levels. I want to predict the water level with the data in the other matrices. Basically, * mod<-lm(matrix1 ~ matrix2+matrix3)* ( What looks like a minus is meant to be the wiggly minus.) Of course I could dissemble the matrices and paste

Hi, I am a begginer in R programming. I am traying to create a a column in my data frame filled down with a number. > df$newcolumn <- number How can I do it? I am considering use rep() but in this case it is necessary know the number of rows in each data base that I have and I would like to do it in a faster ( and more elegant) way. TKs [[alternative HTML version deleted]]

Excellent. That was very helpful. Now I have full control about my NA?s :-) Thank you very much!!! Matthias > > Here is an another way > > count <- is.na(x) + is.na(y) > which( count == 1, arr.ind=TRUE ) > > 'count' gives you the number of missing values at for each > row and column. Then you can find out how many occurances of > both missing,

Dear all, I have about 30,000 matrix (512x512), with values from 1 to N. Each value on a matrix represent a habitat patch on my matrix (i.e. my landscape). Non-habitat are stored as ZERO. No I need to change each 1-to-N values for the same random number. Just supose my matrix is: mymat<-matrix(c(1,1,1,0,0,0,0,0,0,0,0, 0,0,0,0,2,2,2,0,0,0,0, 0,0,0,0,2,2,2,0,0,0,0, 3,3,0,0,0,0,0,0,0,4,4,