R - Filter a vector using a function

Question

I have a function similar to this one:

isGoodNumber <- function(X) 
{
if (X==5) return(TRUE) else return(FALSE)
}

I have a vector:
v<-c(1,2,3,4,5,5,5,5)

I want to obtain a new vector that contains the elements of v where isGoodNumber(v) == TRUE

How do I do this ?

Tried v [ isGoodNumber(v) == TRUE ] but it doesn't work :-)

Thanks !!

question from:https://stackoverflow.com/questions/9265553/r-filter-a-vector-using-a-function

Answer 1

You'll need to Vectorize the function to call it on a vector:

isGoodNumber = Vectorize(isGoodNumber)
v[isGoodNumber(v)]