[R] Integrate na.rm in own defined functions

[Alexander Engelhardt]

Am 20.04.2011 10:59, schrieb Mauro:
> It`s probably an easy question, but couldn`t figure it out.
>
> I`ve defined a function like:
>
> rmse<-function (x){
> dquared<-x^2
> sum1<-sum(x^2)
> rmse<-sqrt((1/length(x))*sum1)
> rmse}
>
> My problem is, that I have NA Values in x and the above function returns NA.
>
> I`m looking for a way to use "na.rm=TRUE" like in for instance
> mean(x,na.rm=TRUE).

If you had no sum function to give the "na.rm=TRUE" parameter, you can 
add the tiny line to your code:
x <- x[!is.na(x)]

Or give your function a na.rm parameter yourself:

rmse<-function (x, na.rm=FALSE){

if(na.rm==TRUE){
  x <- x[!is.na(x)] 		
}

  dquared<-x^2
  sum1<-sum(x^2)
  rmse<-sqrt((1/length(x))*sum1)
  rmse
}