Question

How can we count TRUE values in a logical vector

Answer 1

In the cases of problems where logical vector contains NA values.

a <- c(TRUE, FALSE, NA)
sum(a) # gives you NA
table(a)["TRUE"] # gives you 1
length(a[a==TRUE]) # f3lix answer, gives you 2 (because NA indexing returns values)

sum(a, na.rm=TRUE) # best way to count TRUE values #which gives 1.

You should be careful with the "table" solution, in case there are no TRUE values in the logical vector.
Suppose a <- c(NA, FALSE, NA) or simply a <- c(FALSE, FALSE)

table(a)["TRUE"] # gives you NA for both cases.

Answer 2

Hi,

You can get a count of all values in a vector using table().

If you don't want to include NA, "", specific values in the count, then specify in exclude parameter.

To see count of rows try as below.

syntax: table(vector,exclude = c(values that you want to exclude),useNA = "no")

table(vector,exclude = c("False"),useNA = "no")