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Initializing an array with elements of another array in R

I have an array

a<-c(6,77,98,88,3,10,7,5)

I want to initialize another array with the 1st, 6th, and 8th element i.e. b should look as follows:

b = (6,10,5)

Is there a straightforward way to do this in R?

(I am a beginner, as I am sure you understand, on stack overflow as much as on R. I couldn't find the exact thing I am looking for - maybe I am using the wrong terms to search.)

Solution

  • We can use indexing in replace. Assuming that we need a vector with length 8, initialize with numeric (gives a vector of 0's), then replace using an index with the vector 'b'

    replace(numeric(8), c(1, 6, 8), b)
#[1]  6  0  0  0  0 10  0  5

    If we need to initialize as missing values

    replace(rep(NA_integer_, 8), c(1, 6, 8), b)

    If we want to extract 1, 6, 8 elements from 'a'

    b <- a[c(1, 6, 8)]