Find the First, Second, n Non-sequential Position of a Value in a Vector

Source: R/findFirst.R

This function returns the location of the first, second, third (and so on) occurrence of a specified non-sequential value in a vector.

findFirst(invec, value, event)

Arguments

invec

The input vector.
value

The value you are looking for.
event

The desired position to be returned.

Value

A vector of length 1.

References

http://stackoverflow.com/q/22049035/1270695

Author

Ananda Mahto

Examples


set.seed(1)
a <- sample(LETTERS[1:5], 20, TRUE)
a
#>  [1] "A" "D" "A" "B" "E" "C" "B" "C" "C" "A" "E" "E" "B" "B" "A" "E" "E" "A" "A"
#> [20] "E"

## Note the difference between the following.
## The value "2" is skipped because it is sequential.
which(a == "B")
#> [1]  4  7 13 14

findFirst(a, "B", 2)
#> [1] 7