Explain how to perform vector indexing and slicing in R.
Indexing is defined as selecting an element from a vector present in a particular index. In R, indexing starts from 1 and is denoted by [] bracket
On the other hand, slicing is defined as selecting a part of elements present in a vector by denoting the index notation.
To perform vector indexing and slicing, we have to assign a vector
v1 <- c(100,200,300)
v2 <- c('a','b','c')
Indexing works by using brackets and passing the index position of the element as a number.
# Grab second element
v1[2]
Output: 200
v2[2]
Output: 'b'
We can perform multiple indexing also.
v1[c(1,2)]
Output: 100 200
To perform slicing we can use a colon (:) to indicate a slice of a vector. The format is:
vector[start_index:stop_index]
v <- c(1,2,3,4,5,6,7,8,9,10)
v[2:4]
Output: 2 3 4