match

match(x, y)

Identify where the elements of x are located in y.

• x – A vector.
• y – A vector.

Example. Vectors x and y are initialized, then we look for where the elements of xmatch those of y. Notice that only the first occurrence of each element of x is reported. Additionally, since 80 is not found, NA is returned for its location.

> set.seed(5)
> x <- c(1, 4, 5, 80)
> y <- c(2, 9, 8, 4, sample(15), 1)
> x
[1]  1  4  5 80
> 
> y
 [1]  2  9  8  4  4 10 12 15  2  8  5  7 14  1 11  9
[17]  6 13  3  1
> 
> match(x,y)
[1] 14  4 11 NA

> match(a,b,nomatch = -1)
[1] -1  1 -1 -1  4  5 -1 -1  1