 Apr 19, 2018 802 views

## 1 answer to this question.

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. answered Apr 19, 2018 by
• 3,690 points

## How to count the number of elements with the values in a vector?

You have various options to count the ...READ MORE

## How can I delete multiple values from a vector in R?

The %in% operator tells  which elements are ...READ MORE

## How to remove NA values from a Vector in R?

using the function "complete.cases" for example, if you ...READ MORE

## How to write a custom function which will replace all the missing values in a vector with the mean of values in R?

Consider this vector: a<-c(1,2,3,NA,4,5,NA,NA) Write the function to impute ...READ MORE

## How can I find number of rows in a dataframe, and how to find the number of rows that dont have null values

To know the number of columns in ...READ MORE

## How can you find total number of null values in a dataset column wise?

You can write a custom sapply function ...READ MORE

+1 vote

## Custom Function to replace missing values in a vector with the mean of values

You have missed out on "na.rm=TRUE" inside ...READ MORE

## How to count unique values in R?

You can get the information printed in ...READ MORE