On Thu, May 3, 2012 at 10:43 AM, Christopher Kelvin <chris_kelvin2001 at yahoo.com> wrote: > Is there a command i can issue to replace the NA with zero (0) even if it is after generating the data? Chris, I didn't try your example code, so this suggestion is far more general, but you might try something along the lines of: x[which(is.na(x))] <- 0 Best, James