The sum() function used to calculate sum of a numeric vector, list or data frame.

The following method shows how you can do it with syntax.

Method 1: Use sum() Function

sum(vector.na.rm=TRUE)

The following example shows how to use sum() function in R.

Use sum() Function to Sum Values in Vector

Let’s see how we can calculate sum of values in vector:

# Define vector
vector1 <-c(20,25,27,29,30,32,39,40)

# Find sum of vector values
sum(vector1)

Output:

[1] 242

As the output shows addition of all elements of vector.

Use sum() Function to Sum Values in Vector with Null Values

Suppose vector having null values in it then how we can calculate sum of values in vector:

# Define vector
vector1 <-c(20,NA,27,29,30,NA,39,NA)

# Find sum of vector values
sum(vector1,na.rm=TRUE)

Output:

[1] 145

The output shows the sum of all values in vector. It will avoid or remove null values while calculating sum.

Use sum() Function to Find Sum of Values of Variable

You can use sum() function to calculate the sum of variable of dataframe:

# Create dataframe
df <- data.frame(Machine_name=c("A","B","C","D","A","A","G","B"),
                 Temperature=c(12,9,14,13,18,28,22,23),
                 Pressure=c(20,25,27,29,30,32,39,40))

# Find sum of values of Temperature column of dataframe                 
sum(df$Temperature)

Output:

[1] 139

Here the output shows sum of values of Temperature column of dataframe.

Use sum() Function to Find of Sum of Values of Multiple Variables

You can apply sum() function on multiple variables of dataframe to calculate sum of values:

# Create dataframe
df <- data.frame(Machine_name=c("A","B","C","D","A","A","G","B"),
                 Temperature=c(12,9,14,13,18,28,22,23),
                 Pressure=c(20,25,27,29,30,32,39,40))

# Find sum of values of Temperature,Pressure columns of dataframe                 
sapply(df[ , c('Temperature', 'Pressure')], sum)

Output:

Temperature    Pressure 
        139         242

The output shows sum of values for Temperature and Pressure column respectively.

Note that you can apply sum() function on numeric dataset to calculate sum.