Compute the Sum of Rows of a Matrix or Array in R Programming – rowSums Function
rowSums Function in R
rowSums() function in R Programming Language is used to compute the sum of rows of a matrix or an array.
Syntax:
rowSums(x, na.rm = FALSE, dims = 1)
Parameters:
x: array or matrix
dims: Integer: Dimensions are regarded as ‘rows’ to sum over. It is over dimensions dims+1,…
Compute the Sum of Rows of a Matrix in R Programming
We will create one simple matrix and with the help of rowsum function, we will calculate the sums of the rows of the matrix.
R
# R program to illustrate # rowSums() function # Initializing a matrix x <- matrix(rep(2:10), 3, 3) # Printing Matrix print(x) # Calling the rowSums() function rowSums(x) |
Output:
[, 1] [, 2] [, 3]
[1, ] 2 5 8
[2, ] 3 6 9
[3, ] 4 7 10
[1] 15 18 21
Compute the Sum of Rows of a Array in R Programming
We will create one simple array and with the help of rowsum function, we will calculate the sums of the rows of the array.
R
# R program to illustrate # rowSums function # Initializing a 3D array x <- array(1:8, c(2, 2, 2)) # Printing the array print(x) # Calling the rowSums() function rowSums(x, dims = 1) |
Output:
,, 1
[, 1] [, 2]
[1, ] 1 3
[2, ] 2 4,, 2
[, 1] [, 2]
[1, ] 5 7
[2, ] 6 8
[1] 16 20
Compute the Sum of Rows of a data frame in R Programming
We will create one simple data frame and with the help of rowsum function, we will calculate the sums of the rows of the dataframe.
R
# Create a sample data framedata <- data.frame( ID = c(1, 2, 3), Val1 = c(10, 20, 30), Val2 = c(5, 15, 25))# Display the original data frameprint(data)# Calculate the row sums using rowSums()row_sums <- rowSums(data[, c("Val1", "Val2")])# Display the data frame with row sumsprint(row_sums) |
Output:
ID Val1 Val2
1 1 10 5
2 2 20 15
3 3 30 25
[1] 15 35 55
Use rowSums() with NA Values in Data Frame
Now we create one dataset with missing values and then we use rowsums function to calculate sum of rows of missing values.
R
# Create a sample data frame with missing valuesdata <- data.frame( ID = c(1, 2, 3), Val1 = c(10, NA, 30), Val2 = c(5, 15, NA))# Display the original data frame with missing valuesprint("Original Data Frame with Missing Values:")print(data)# Calculate the row sums, treating missing values as zerorow_sums <- rowSums(data[, c("Val1", "Val2")], na.rm = TRUE)# Display the data frame with row sumsrow_sums |
Output:
ID Val1 Val2
1 1 10 5
2 2 NA 15
3 3 30 NA
[1] 15 15 30
We use na.rm = TRUE argument in rowSums() is used to treat missing values as zero during the sum calculation.
Use rowSums() with Specific Rows
Now we can create one dataframe and select few specific rows for calculate the sum of the rows using rowSums function.
R
# Create a sample data frame with missing valuesdata <- data.frame( ID = c(1, 2, 3), Val1 = c(10, NA, 30), Val2 = c(5, 15, NA), val3 = c(NA, 20, 5), val4 = c(15, 25, NA))# Display the original data frame with missing valuesprint("Original Data Frame with Missing Values:")print(data)# Calculate the row sums, treating missing values as zerorow_sums <- rowSums(data[, c("Val2", "val4")], na.rm = TRUE)# Display the row sumsprint("Row Sums:")print(row_sums) |
Output:
ID Val1 Val2 val3 val4
1 1 10 5 NA 15
2 2 NA 15 20 25
3 3 30 NA 5 NA
[1] "Row Sums:"
[1] 20 40 0
Here we are select second and forth rows for the calculating sum off the specific rows.
