How to Remove NA from Vector?

In R, NA denotes ‘Missing Values’ or ‘Not Available’. To remove NA values from a vector, you can use the na.rm() or is.na() functions. Additionally, R provides various other methods to eliminate NA values from a vector.

When you perform an arithmetic operation on an R vector containing NA values, the result will be NA. Generally, any operation involving NA results in NA. Therefore, it is advisable to clean the vector by removing all NA values before performing arithmetic operations.

Alternatively, you can also replace NA with 0 before applying any arithmetic or statistical operations.

1. Quick Examples of Remove NA from Vector

Following are quick examples of how to remove NA values from R Vector.


# Quick Examples

# Create Vector
ids <- c(10,5,NA,15,10)

# Using is.na()
x <- ids[!is.na(ids)]

# Using na.rm=TRUE
x <- max(ids, na.rm=TRUE)

# Using na.omit()
x <- na.omit(ids)

# Remove NA from string Vector.
states = c('NY','DC',NA,'CA','NV',NA)
x <- na.omit(states)

# Using exclude
x <- na.exclude(states)
print(x)

2. Remove NA from Vector using is.na()

The is.na() indicates which elements are missing. The is.na(x) function returns a logical vector of the same size as x with value TRUE when the corresponding element in x is NA.

2.1 is.na() Syntax

The following is the syntax of the is.na() function.


# Syntax
vector[!is.na(vector)]

2.2 Remove NA from Vector Example

is.na() function is used to remove NA values from the vector. This function returns a vector consisting of logical values (i.e. TRUE or FALSE), whereby TRUE indicates a missing value.


# Using is.na()
ids <- c(10,5,NA,15,10)
is.na(ids)

# Output
# [1] FALSE FALSE  TRUE FALSE FALSE

By negating the result you will get a logical vector with FALSE at the position of NA value. Now use this result on vector bracket notation to remove elements at the FALSE position this ideally removes NA values from the vector.


# Remove NA values from Vector
x <- ids[!is.na(ids)]
print(x)

# Output
# [1] 10  5 15 10

3. Using na.rm=TRUE

When used na.rm=TRUE with any arithmetic or statistical functions it removes the NA values from vector while performing operations. By default FALSE is set to na.rm.

Following is the syntax of the na.rm=TRUE and its usage with max() function.


# Syntax of na.rm=TRUE 
max(vector, na.rm = TRUE)

Lets use this and calculate sum(), max() and mean() for the Vector. If you don’t remove the NA values from the vector, then all these operations returns NA as a result.


# Using na.rm=TRUE
x <- sum(ids, na.rm=TRUE)
print(x)

x <- max(ids)
print(x)

x <- mean(ids, na.rm=TRUE)
print(x)

4. Remove NA from Vector using na.omit()

4.1 Syntax of na.omit()

Following is the syntax of the na.omit() function.


# Syntax of na.omit()
na.omit(vector)

4.2 Delete NA values from Vector

The following R program removes all NA values from the vector.


# Using na.omit()
x <- na.omit(ids)
print(x)

Yields below output


# Output
[1] 10  5 15 10
attr(,"na.action")
[1] 3
attr(,"class")
[1] "omit"

5. Remove NA from Vector using na.exclude()

5.1 Syntax of na.exclude()

Following is the syntax of the na.exclude() function.


# Syntax of na.exclude()
na.exclude(vector)

5.2 Drop NA Values from Vector