The rowSums() function in R is **“used to calculate the sum of values in each row of a matrix or data frame.“**

**Syntax**

`rowSums(x, na.rm=FALSE) `

**Parameters**

**x:**It is the name of the matrix or data frame.

**na.rm:**It is a logical argument. If**TRUE,**NA values are ignored.

**Example 1: Use the rowSums() with Data Frame**

The** rowSums()** to find the sum of the values in each data frame row.

```
library(dplyr)
# Create a data frame.
df <- data.frame(
x = c(11, 21, 31, 41, 51),
y = c(1, 2, 3, 4, 5)
)
# Calculate the row sums.
rowSums(df)
```

**Output**

```
[1] 12 23 34 45 56
```

**Example 2: ****Use rowSums() with NA Values in Data Frame**

You can find the sum of the values in each data frame row when there are **NA** values in some rows using the **na.rm = TRUE** argument.

```
library(dplyr)
# Create a data frame.
df <- data.frame(
x = c(11, 21, 31, NA, 51),
y = c(1, 2, NA, 4, 5)
)
# Calculate the row sums.
rowSums(df, na.rm = TRUE)
```

**Output**

```
[1] 12 23 31 4 56
```

**Example 3: Use the rowSums() with specific rows**

You can use the **rowSums()** to find the sum of the values in specific rows of a data frame.

```
library(dplyr)
# Create a data frame.
df <- data.frame(
x = c(11, 21, 31, NA, 51),
y = c(1, 2, NA, 4, 5),
z = c(19, 46, NA, 30, 53),
w = c(11, 11, 20, 39, 49)
)
rowSums(df[c(1, 2, 3), ], na.rm = TRUE)
```

**Output**

```
1 2 3
42 80 51
```

**Example 4: Use the rowSums() with matrix**

To calculate the sum of row values of the matrix in R, use the **“rowSums()”** function.

```
rv <- rep(1:4)
mtrx <- matrix(rv, 2, 2)
mtrx
cat("The sum of rows is: ", "\n")
rowSums(mtrx)
```

**Output**

```
[,1] [,2]
[1,] 1 3
[2,] 2 4
The sum of rows is:
[1] 4 6
```

That’s it.

Krunal Lathiya is a seasoned Computer Science expert with over eight years in the tech industry. He boasts deep knowledge in Data Science and Machine Learning. Versed in Python, JavaScript, PHP, R, and Golang. Skilled in frameworks like Angular and React and platforms such as Node.js. His expertise spans both front-end and back-end development. His proficiency in the Python language stands as a testament to his versatility and commitment to the craft.