I'm looking to write a function named insert(x, where, what) that inserts a value (what) at a given position (where) in a vector (x)
If the given position exceeds the dimension of a vector there should be a warning message that prints out and the positions between the last element of the vector and the inserted value should be filled with NAs
This is what I have so far but it results in a vertical vector:
x <- 1:10
insert <- function (x, where, what)
{if (where>10) c(append(x, what, after = where-1),print("Warning message: In insert(a, 11 , 0) : 11 exceeds the dimensions of the vector"))
else
append(x, what, after = where-1)}
insert(x, 5, 0)
insert(x, 11, 0)
insert(x,15,0)
Below is the desired output:
a <- 1:10
insert(a, 5, 0)
[1] 1 2 3 4 0 5 6 7 8 9 10
insert(a, 11, 0)
[1] 1 2 3 4 5 6 7 8 9 10 0
Warning message:
In insert(a, 11, 0) : 11 exceeds the dimension of the vector
insert(a, 15, 0)
[1] 1 2 3 4 5 6 7 8 9 10 NA NA NA NA 0
Warning message:
In insert(a, 15, 0) : 15 exceeds the dimension of the vector
1 Answer
One approach to achieve your desired result may look like so:
insert <- function(x, where, what) {
lenx <- length(x)
if (where > lenx) {
warning(paste0(where, " exceeds the dimensions of the vector."))
res <- c(x, rep(NA, where - lenx - 1), what)
} else {
res <- c(x[seq(where - 1)], what, x[seq(where, lenx)])
}
return(res)
}
x <- 1:10
insert(x, 5, 0)
#> [1] 1 2 3 4 0 5 6 7 8 9 10
insert(x, 11, 0)
#> Warning in insert(x, 11, 0): 11 exceeds the dimensions of the vector.
#> [1] 1 2 3 4 5 6 7 8 9 10 0
insert(x, 15, 0)
#> Warning in insert(x, 15, 0): 15 exceeds the dimensions of the vector.
#> [1] 1 2 3 4 5 6 7 8 9 10 NA NA NA NA 0
