similar to: Sum the cell of a vector

I have a question regarding the most efficient way to select a substring of a vector: I have a vector of value v, and I want to select a subspace of this vector called w such that: w=v[1:n] where sum(w) = x I am interested in what you thing would be the most efficient way to do this - I would like to avoid slowing down my simulations as much as possible. Thank you very much for any help that

Dear R users, I am currently writing a MCMC algorithm for spatial Poisson model. One problem which I need to solve is as follows: I have a vector X[1:J] which describes characteristics of cells of a rectangular grid. Further, for each cell I have a list of adjascent cells adj[] and the vector listing numbed of adjascent cells num[]. Thus if I want to list cells adjascent to cell i I write

Dear colleagues, I have a data set that looks roughly like this; mydat<-data.frame(state=c(rep("Alabama", 5), rep("Delaware", 5), rep("California", 5)), news=runif(15, min=0, max=8), cum.news=rep(0, 15)) For each state, I'd like to cumulatively sum the value of "news" and make that put that value in cum.news. I'm trying as follows but I get

Hello I would like to calculate a weighted line integral. The integral is calculated by the cells that this lines trasverses (the small cells belong to matrix (m*n) that represent the value that a specific area has. I need to calculate the weights by finding out how much the line touches or impinges inside a cell. The weight is less if a line just touches one of the four edges of a square

Dear all I need to run an anova from a factorial model y_{ijk}=\alpha_i+\beta_j+(\alpha\beta)_{ij}+e_{ijk} and calculate type II and III sums of square, but I have an empty cells, so anova function from package car fail. (I believe) y<-c(7,13,6,10,8,11,8,3,7,5,65) a<-as.factor(c(1,1,2,2,3,3,3,1,1,1,2)) b<-as.factor( c(rep(1,7),rep(2,4)) ) table(b,a) # cell (2,3) is empty

Hello all I would like to ask your help use mapply. I have a function called findCell that takes two arguments(x,sr) where x is a vector of size two (e.g x<-c(2,3) and sr is a matrix. I would like to call many times the findCell function (thus I need mapply) for different x inputs but always for the same sr. as x is a vector of size two (two cells) I want to pass inside inside the following

Greetings Friends, I would be grateful if you can help me undestand how to make my R code more efficiently. I have read in R intoductory tutorial that a for loop is not used so ofter (and is not maybe not that efficient) compared to other languages. So I am trying to build understanding how to get the equivalent of a for loop using more R-oriented thinking. If I got it right one way to do that

Hi, x <- c(rep(1800000003L, 10000000), -rep(1200000002L, 15000000)) This is correct: > sum(as.double(x)) [1] 0 This is not: > sum(x) [1] 4996000 Returning NA (with a warning) would also be acceptable for the latter. That would make it consistent with cumsum(x): > cumsum(x)[length(x)] [1] NA Warning message: Integer overflow in 'cumsum'; use

Hi, I have a DF like this: DF = data.frame(read.table(textConnection(" A B C 1 b1 1999 0.25 2 c1 1999 0.25 3 d1 1999 0.25 4 a2 1999 0.25 5 c2 1999 0.25 6 d2 1999 0.25 7 a3 1999 0.25 8 b3 1999 0.25 9 d3 1999 0.25 10 a4 1999 0.25 11 b4 1999 0.25 12 c4 1999 0.25 13 b1 2001 0.5 14 a2 2001 0.5 15 b1 2004 0.33 16 c1 2004 0.33 17 a2 2004 0.33 18 c2 2004

Hi I noticed a small inconsistency when using sum() vs cumsum() I have a char-based series > tryjpy$long [1] "0.0022" "-0.0002" "-0.0149" "-0.0023" "-0.0342" "-0.0245" "-0.0022" [8] "0.0003" "-0.0001" "-0.0004" "-0.0036" "-0.001" "-0.0011"

>>>>> Tomas Kalibera >>>>> on Tue, 25 Aug 2020 09:29:05 +0200 writes: > On 8/23/20 5:02 PM, Rory Winston wrote: >> Hi >> >> I noticed a small inconsistency when using sum() vs cumsum() >> >> I have a char-based series >> >> > tryjpy$long >> >> [1]

I recently traced a bug of mine to the fact that cumsum(s)[length(s)] is not always exactly equal to sum(s). For example, x<-1/(12:14) sum(x) - cumsum(x)[3] => 2.8e-17 Floating-point addition is of course not exact, and in particular is not associative, so there are various possible reasons for this. Perhaps sum uses clever summing tricks to get more accurate results? In some

Hi, Maybe I have not been looking in the right spot, but, I have not been able to fine a command to automatically calculate the running cumulative sum of a vector. Is there such a command? Example of current code: > eig$values [1] 678.365651 6.769697 2.853783 > prop<-eig$values/sum(eig$values) > prop [1] 0.986012163 0.009839832 0.004148005 >

I have vector X of length N that I want to have a running sum for (called Y). I just need max(Y). I do this with a "for" loop like so: Y <- vector(length=N) Y[1] <- X[1] for (i in 2:N) { Y[i] <- Y[i-1]+X[i] } return(max(Y)) Is there a faster way to do this? Thanks, Sean

Hello. I want to print the value a matrix has. The matrix's size is not too big (100*100 cells). I tried print(matrixname) but as it does not fit very well on my screen R splits it into several small matrixes that do overflow my screen. IS it possible somehow to display this matrix as one (even if this needs to go fullscreen) . There might be some function for that like plot cells or

I have a vector of values X = seq(1:10) I want to get another vector V of with sample (with replacement) of X but with a constrain: V will have as much elements as those necessary to V sum exactly 10. If the N-th value of V make the sum greater than 10, it's is subtracted with the difference to achieve the constrain. I don't know how to achieve this. with a while?

Hi all, I'm trying to figure out a way to create a data graphic that I haven't ever seen an example of before, but hopefully there's an R package out there for it. The idea is to essentially create a heatmap, but to allow each column and/or row to be a different width, rather than having uniform column and row height. This is sort of like a Marimekko chart in appearance, except that

I have a bunch of jpg files that I need to count cells on. Some cells are green and some cells are red. Is there a function like locator that I could use to manually count the cells? I would like to be able to click on a cell, have it marked so I don't count it again and have a counter keep track. Locator comes close but I would only be able to count one colour at a time. Is there a way I

Well, here's one way to do it: (dat is your example data frame) Cutoff <- seq(0, .15, .01) Pop <- with(dat, sapply(Cutoff, \(p)sum(Totpop[Pct >= p]))) I think there must be a more efficient way to do it with cumsum(), though. Cheers, Bert On Sat, Oct 14, 2023 at 12:53?AM Jason Stout, M.D. <jason.stout at duke.edu> wrote: > > This seems like it should be simple but I

Dear all, in one part of my code I want to sum two vectors element-wise the problem is that either the 1st vector or the 2nd vector always have one or two less elements example of my problem In TotalVector + (datalist2[[1]]$dataset$Results[[j]]$Results[[time]]$Sweep) :   Länge des längeren Objektes          ist kein Vielfaches der Länge des kürzeren Objektes Browse[1]> str(TotalVector)  int