As Joshua said, in your example sim isn't be declared anywhere (neither in the environment nor as an argument in a function), but you might try something more R-ish:
prop.doubles <- function(sim){ sum(sample(1:6, sim,replace=T)==sample(1:6,sim,replace=T))/sim } prop.doubles(1000) Cheers, Jeff. On Tue, Oct 5, 2010 at 2:30 AM, Joshua Wiley <jwiley.ps...@gmail.com> wrote: > On Mon, Oct 4, 2010 at 9:13 PM, Lemarian WallaceIII <tott...@yahoo.com> wrote: >> Im trying to simulate the rolling of a pair of dice >> >> this is my function: >> #function to simulate tosses of a pair of dice >> #from the simulation, the program returns the empirical probability of >> #observing a double >> count <- 0 >> for(j in 1:sim){#begin loop >> die1 <- sample(1:6,1) >> print(die1) >> die2 <- sample(1:6,1) >> print(die2) >> count <- ifelse(die1 == die2, count + 1, count) >> }#end loop >> emprob <- count/sim >> return(count,emprob) >> } #end program >> >> >> these are the errors that keep coming up: >> Error in 1:sim : 'sim' is missing > > You need to define an object called 'sim', otherwise you are telling R > to go look up the value of a non-existent variable. Does your > function have a first part? All I am seeing is the body and the end. > > Josh > >> >> >> How do I correct this? >> >> >> >> [[alternative HTML version deleted]] >> >> >> ______________________________________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> >> > > -- > Joshua Wiley > Ph.D. Student, Health Psychology > University of California, Los Angeles > http://www.joshuawiley.com/ > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.