In R, how can I count instances of a dummy variable =1?

Question

Closed. This question needs details or clarity. It is not currently accepting answers. question from:https://stackoverflow.com/questions/65946613/in-r-how-can-i-count-instances-of-a-dummy-variable-1

Answer 1

If variable X is an integer;

mtcars$am
[1] 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1
> sum(mtcars$am)
[1] 13

If variable X is a factor (or character);

> sum(as.factor(mtcars$am) == "1")
[1] 13

You can check by using class();

> class(mtcars$am)
[1] "numeric"
> class(as.factor(mtcars$am))
[1] "factor"

mtcars is a build in dataset for R (you can use data()) to see a list of built in datasets.