How to count TRUE values in r

689 Asked by AvaBlack in Data Science , Asked on Jun 14, 2021

In R, what is the most efficient/idiomatic way to count the number of TRUE values in a logical vector? I can think of two ways:

z <- sample(c(TRUE, FALSE), 1000, rep = TRUE)
sum(z)
# [1] 498
table(z)["TRUE"]
# TRUE 
#  498

Which do you prefer? Is there anything even better?

Answered by Aashish chaursiya

To count TRUE in r values in a logical vector, you can use the following functions:

z <- sample(c(TRUE, FALSE), 10000, rep = TRUE)

length(z[z== TRUE])

[1] 5095

sum(z)

[1] 5095

table(z)["TRUE"]

TRUE 

5095

In vector where there are NA values:

z <- sample(c(TRUE, FALSE,NA), 10000, rep = TRUE)

sum(z, na.rm = TRUE)

[1] 3265

table(z)["TRUE"]

TRUE 

3265 

The length function counts the return value of NA’s as a TRUE value.

length(z[z== TRUE])

[1] 6671

In vectors having no TRUE values:

sum(z, na.rm = TRUE)

[1] 0

length(z[z== TRUE])                     #Counts return values of NA as TRUE

[1] 5004

table(z)["TRUE"]                          #Returns NA

 

  NA

So the best solution to count TRUE values is to use the sum() function along with the na.rm argument as TRUE.

How to count TRUE values in r

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