similar to: Odd behaviour of identical()

Hello. I've observed some odd behaviour. Most likely, it is already known and explained somewhere, but I can't find an explanation anywhere, so I would appreciate being pointed in the right direction. The issue with the following code is self explanatory: > mat <- matrix(c(c(1,1,1),c(2,2,2)),nrow=3) > mat[,c(1:3%/%2)] [,1] [,2] [1,] 1 1 [2,] 1 1 [3,] 1 1

Dear All, I'm dealing with a case, where 'manhattan' distance of each of 100 vectors is calculated from 10000 other vectors. For achieving this, following 4 scenarios are tested: 1) scenario 1: > x<-read.table("query.vec") > v<-read.table("query.vec2") > d<-matrix(nrow=nrow(v),ncol=nrow(x)) > for (i in 1:nrow(v)){ + d[i,]<-

Hello everyone, Considering the following code sample : ---- indexes <- function(vec) { vec <- which(vec==TRUE) return(vec) } mat <- matrix(FALSE, nrow=10, ncol=10) mat[1,3] <- mat[3,1] <- TRUE ---- Issuing apply(mat, 1, indexes) returns a 10-cell list, as expected. Now if I do: ---- mat[1,3] <- mat[3,1] <- FALSE apply(mat, 1, indexes) ---- I would expect a

Dear list members, Where can I find code for computing the p*p variance-covariance matrix given a vector of p variances (ordered varA, varB, ..., varp) and a vector of all possible correlations (ordered corAB, corAC, ..., corp-1,p)? I know that the covariance between 2 variables is equal to the product of their correlation and their standard deviations: corAB * varA^.5 * varB^.5 and so:

The rules for conformability of objects required for various operators remain a mystery as do some related problems like the rules for recycling in creating arrays etc. Would someone be able to direct me to where such rules are stated? In a related vein, there are all manner of operations that are readily coded in Gauss or in MATA that fail, often mysteriously, in R. Are there some

>>>>> Gabor Grothendieck >>>>> on Mon, 16 Sep 2024 11:21:55 -0400 writes: > Suppose we have `dat` shown below and we want to find the the `y` value > corresponding to the last value in `x` equal to the corresponding component > of `seek` and we wish to return an output the same length as `seek` using > `findInterval` to perform the

I am trying to convert a string to a vector, and I'm stuck! Suppose you have a string of numbers (string) that you want to convert to a vector (vec). I am able to split the string turning it into a list by using strsplit, but this makes a list, which I can't seem to access the way that I'd like to (it becomes a character list of only one(?!?) element.)

Thanks Bill and Michael for taking the time to share your knowledge! As a further background to my question, here are two examples that I forgot to include in my original post (reminded by Michael's answer). I swapped the i and j arguments in `[.data.frame` and `[<-.data.frame`. With warnings, but else without (?) problem. Using Bill's data: `[.data.frame`(x = d, i = 1, j = 2) # [1]

I have one other problem and then I'll stop and get back to writing. I want to plot a missing data matrix (the R matrix a la Little and Rubin) to graphically depict where the missing data lie in the matrix. Some statistical packages produce a graphical depiction of the missing data patterns by plotting the matrix, color-coding the plot with contrasting colors for either missing or

tl;dr: Why are named arguments discouraged in `[.data.frame`, `[<-.data.frame` and `[[.data.frame`? (because this question is of the kind 'why is R designed like this?', I though R-devel would be more appropriate than R-help) ############################# Background: Now and then students presents there fancy functions like this:

Hello, I am struggling with detecting successive digits in a numerical series vector. Here is an example: vec <- c(1, 15, 26, 29, 30, 31, 37, 40, 41) I want to be able to detect 29, 30, 31 and 40, 41. Then, I would like to delete the successive digits from the vector. 1, 15, 26, 29, 37, 40 Cheers -- View this message in context:

Hi, In the example you showed: m1<- matrix(0,length(vec),max(vec)) 1*!upper.tri(m1) #or ?m1[!upper.tri(m1)] <-? rep(rep(1,length(vec)),vec) #But, in a case like below, perhaps: vec1<- c(3,4,5) ?m2<- matrix(0,length(vec1),max(vec1)) ?indx <- cbind(rep(seq_along(vec1),vec1),unlist(tapply(vec1,list(vec1),FUN=seq),use.names=FALSE)) m2[indx]<- 1 ?m2 #???? [,1] [,2] [,3] [,4] [,5]

Hi, I have a (correlation) matrix and I want to select a subset of its cells depending on the combination of their column and row names. This illustrates my problem: mtrx <- matrix(c(1,2,3,4,5,6,7,8,9), nrow=3, ncol=3, dimnames = list(c('c132','c432', 'c233'), c('r132','r233', 'r432')))> mtrx r132 r233 r432c132 1 4 7c432 2

Dear all, Does anyone have any idea on how to speed up the for() loop below. Currently it takes approximately 2 minutes and 30 seconds. Because of the size of Nsim and N, simulating a multivariate normal (instead of simulating Nsim times a vector of N normal distributions) would require too much memory space. Many thanks for your kind help, Simona N=3000 PD=runif(N,0,1) cutoff.=qnorm(PD)

Hello, I use R 2.10, and I am new in R (I used to use SAS and lately Stata), I am using XP. I have a data which has a data.frame format called x.df (read from a csv file). I want to take from this data observations for which the variable "Code" starts with an "R". I took all the Code and put them into a vector vec<-grep("R[A-Z][A-Z]",x.df$Code,value=TRUE) Then I

Hi, I am trying to get different combinations of a vector of different size and find their sum. For example, if I have a vector (i,j) where i and j can be anything from 0 to 5, i get these combinations (0,0), (0,1), (1,0), (1,1), (2,0), ...... (5,5) and find sum of these as 0, 1, 1, 2, ..... , 10. I used outer functions to get this and it worked. What if I have a vector (i,j,k) where all i, j ,

Hello. I ran a simulation that took a few days to complete, and want to analyze the results, but have just realized that I (idiotically) did not assign the output to a variable when I intitiated the simulation. Is there any way to retrieve the last output produced by R so that these last few days were not a waste? Thank you very much. -- View this message in context:

Dear useRs, I want to write a function that generates all the possible combinations of diff(). Example: If my vector has length 5, I need the diff() until lag=4 -> c(diff(my.vec), diff(my.vec, lag=2), diff(my.vec, lag=3), diff(my.vec, lag=4)) If it has length 4, I need until lag=3 -> c(diff(my.vec), diff(my.vec, lag=2), diff(my.vec, lag=3)) So, it must be until lag=(length(my.vec)-1).

The attached patch adds some sanity checks to the "type" argument of quantile(). Output from the following commands show the change of behavior with the current patch: vec <- 1:10 quantile(vec, type = c(1, 2)) quantile(vec, type = 10) quantile(vec, type = "aaa") quantile(vec, type = NA_real_) quantile(vec, type = 4.3) quantile(vec, type = -1) Current behavior

On Tuesday 16 December 2008 01:03:36 Evan Cheng wrote: > FYI. http://leonardo-m.livejournal.com/73732.html > > If anyone is motivated, please file bugs for the losing cases. Also, > it might make sense to incorporate the tests into our nightly tester > test suite. FWIW, I just ported my ray tracer benchmark to C and found that llvm-gcc gives much worse performance than gcc on x86