R - Variance

The R var() function returns variance of all elements present in the argument. The syntax for using this function is given below:

Syntax

var(x, na.rm = FALSE)

Parameters

`x`	`Required.` Specify numeric vector.
`na.rm`	`Optional.` Specify TRUE to remove NA or NaN values before the computation. Default is FALSE.

Return Value

Returns variance of all elements present in the argument.

Example:

The example below shows the usage of var() function.

vec <- c(10, 55, 25, -56, 30, 99)
cat("Variance of all elements of vec:", var(vec), "\n")

mat <- matrix(c(10, 55, 25, -56, 30, 99), ncol=2)
cat("\nThe matrix contains:\n")
print(mat)
cat("\nVariance of elements along first column:", var(mat[,1]))
cat("\nVariance of elements along second column:", var(mat[,2]))
cat("\nVariance of elements along first row:", var(mat[1,]))
cat("\nVariance of elements along second row:", var(mat[2,]))

The output of the above code will be:

Variance of all elements of vec: 2631.767 

The matrix contains:
     [,1] [,2]
[1,]   10  -56
[2,]   55   30
[3,]   25   99

Variance of elements along first column: 525
Variance of elements along second column: 6030.333
Variance of elements along first row: 2178
Variance of elements along second row: 312.5

Using na.rm parameter

The na.rm parameter can be set TRUE to remove NA or NaN values before the computation.

Example:

Consider the example below to see the usage of na.rm parameter.

v1 <- c(10, 55, 25, -56, 30, 99, NA)
v2 <- c(10, 55, 25, -56, 30, 99, NaN)

cat("Variance of all elements of v1:", var(v1), "\n")
cat("Variance after removing NA:", var(v1, na.rm=TRUE), "\n")

cat("\nVariance of all elements of v2:", var(v2), "\n")
cat("Variance after removing NaN:", var(v2, na.rm=TRUE), "\n")

The output of the above code will be:

Variance of all elements of v1: NA 
Variance after removing NA: 2631.767 

Variance of all elements of v2: NA 
Variance after removing NaN: 2631.767

❮ R Statistical Functions