[R] prblem with NA

[Erik Iverson]

Hello -

kayj wrote:
> 
> Hi all
> 
> I have a data set with the total number of columns =ncol, and the total
> number of rows=nrow. I am trying to loop over the values and id the value is
> less than or equal to 100 to be changed to 1. if the value is greater than
> 100 , to be changed to 0. if NA , let X[i,j]=NA. I ran into a problem where
> if one row in my data set had all values =NA, then the program does not
> continue working past that row!  
> 
> At some point I get the following error message:
> 
> “Error in if (data [i, j] <= 100) { : missing value where TRUE/FALSE needed”
> 
> Here is the program 
> 
> data<-read.table("fileName.txt", header=F, sep='\t')
> 
> X=data
> for(i in ncol)
> {
> for(j in nrow)
> {
> if(data[i,j]<=100) {X[i,j]=1}
> if(data[i,j]>100) {X[i,j]=0}
> 
> if(is.na(data[i,j])) {X[i,j]=NA}
> }
> }


An alternate, vectorized solution may be:

X <- ifelse(data <= 100, 1, 0)

And as 'data' is a function in the utils package include with R, you 
might consider not naming your variables 'data'.