WebApr 24, 2024 · The outer loop goes over the column, sets the first row in that column to value. Then the inner loop fills up the rest of the rows in that column using the fn. The function itself takes the previous row value as its input. fn <- function (value) { value + 1 } myMatrix <- matrix (NA,5,3) value <- 100 for (col in 1:ncol (myMatrix)) { myMatrix [1 ... WebMar 6, 2012 · Okay, the first thing you need to know is how to append things to a vector. Easily enough the function you want is append: x <- c (1, 2) x <- append (x, 3) will make the vector x contain (1, 2, 3) just as if you'd done x <- (1, 2, 3). The next thing you need to realise is that each member of your target vector is double the one before, this is ...
r - Assigning results of a for loop to an empty matrix - Stack …
WebOct 12, 2024 · Here is a completely generic example on how to fill a matrix using for -loops in R: m = 100 n = 20 o = matrix (data = NA, nrow = m, ncol = n) for ( i in 1:m ) { for ( j in 1:n ) { o [i,j] = rnorm (n = 1) } } Or filling by row: m = 100 n = 20 o = matrix (data = NA, nrow = m, ncol = n) for ( i in 1:m ) { o [i,] = rnorm (n = n) } WebI'm trying to fill an empty matrix with results calculated from a for loop. I don't know how to specify the indexing in my for loop i.e., right now my for loop code does not work and I can't get result into my matrix. Here's a subset of my data: origin 官网地址
How to Use a For-Loop in R (with 18 Code Examples)
Webmat <- matrix (NA, nrow = 3, ncol = 3) [,1] [,2] [,3] [1,] NA NA NA [2,] NA NA NA [3,] NA NA NA Is there an efficient way to populate the matrix with the entries in the third column of the table with R, without having to iterate over the table, isolate the indices and insert value in a for loop? Thanks. r matrix Share Cite WebDec 21, 2013 · You can proceed as follows: #extract the correlation r from LD results tc<-LD.object$"r" #build a three columns matrix with all the pairwise combination of two markers pwm<-combn (row.names (tc),2) pwld<-matrix (NA,nrow=ncol (pwm),ncol=3) pwld [,1:2]<-pwm [1:2,] #Fill the matrix for (aaa in 1:nrow (pwld)) { pwld [aaa,3]<-tc [pwld [aaa,1],pwld ... WebMar 25, 2024 · # Create a matrix mat <- matrix (data = seq (10, 20, by=1), nrow = 6, ncol =2) # Create the loop with r and c to iterate over the matrix for (r in 1:nrow (mat)) for (c in 1:ncol (mat)) print (paste ("Row", r, "and … how to write a drunk person