Return the Index of the First Maximum Value of a Numeric Vector in R Programming – which.max() Function

which.max() function in R Language is used to return the location of the first maximum value in the Numeric Vector.

Syntax: which.max(x)

Parameters:
x: Numeric Vector

Example 1:

# R program to find index of
# first maximum value

# Creating a vector
x <- c(2, 3, 4, 5, 1, 2, 3, 1, 2)

# Calling which.max() function
which.max(x)

# Printing maximum value
x[which.max(x)]

Output:

[1] 4
[1] 5

Example 2:

# R program to find index of
# first maximum value

# Calling pre-defined dataset
BOD$demand

# Calling which.max() function
which.max(BOD$demand)

# Printing maximum value
BOD$demand[which.max(BOD$demand)]

Output:

[1] 8.3 10.3 19.0 16.0 15.6 19.8
[1] 6
[1] 19.8