How to count the Number of Occurrences of Specific Item in the Vector in R - Step by Step Examples

How to count the Number of Occurrences of Specific Item in the Vector in R ?

To count the number of occurrences of a specific item in a vector in R, you can use the sum function along with logical indexing.

In this example,

We create a numeric vector named vec with a set of numerical values.
We define a variable item that holds the value we want to count in the vector.
We use the sum function combined with logical indexing to count the occurrences of item in vec. The logical indexing vec == item creates a logical vector where each element is TRUE if it matches item and FALSE otherwise.
The sum function then adds up the TRUE values, treating them as 1 and FALSE values as 0, resulting in the count of occurrences of item in vec.
Finally, we print the result to standard output using the print function.

vec <- c(1, 2, 3, 2, 2, 4, 5, 2)
item <- 2
count <- sum(vec == item)
print(count)

In this example,

We create a character vector named char_vec with a set of string values.
We define a variable str_item that holds the string we want to count in the vector.
We use the sum function combined with logical indexing to count the occurrences of str_item in char_vec. The logical indexing char_vec == str_item creates a logical vector where each element is TRUE if it matches str_item and FALSE otherwise.
The sum function then adds up the TRUE values, treating them as 1 and FALSE values as 0, resulting in the count of occurrences of str_item in char_vec.
Finally, we print the result to standard output using the print function.

char_vec <- c("apple", "banana", "apple", "cherry", "banana", "apple")
str_item <- "apple"
count <- sum(char_vec == str_item)
print(count)

In this example,

We create a logical vector named log_vec with a set of logical values TRUE and FALSE.
We define a variable log_item that holds the logical value we want to count in the vector.
We use the sum function directly on the logical vector log_vec where each TRUE value is treated as 1 and each FALSE value as 0. This effectively counts the number of TRUE values in log_vec.
If we need to count FALSE values, we can use the logical negation operator ! to flip the values in log_vec and then use the sum function.
Finally, we print the result to standard output using the print function.

log_vec <- c(TRUE, FALSE, TRUE, TRUE, FALSE, TRUE, FALSE)
log_item <- TRUE
count <- sum(log_vec == log_item)
print(count)

In this tutorial, we learned How to count the Number of Occurrences of Specific Item in the Vector in R language with well detailed examples.