Dear all, Thanks for the many replies!
Indeed, the function does not represent my explanation. It should have been: if (x[i] > 170 && x[i] < 1250 && y[j] > 150 && y[j] < 480) Sorry, my mistake. My data looks like this: head(input[,3:4]) x y 1 701 209 2 685 209 3 566 248 4 562 234 5 601 225 6 608 232 Refering to the last post, I guess that my function then should look like something like this: test <- apply(input,1,function(x){ lookzone<-NULL if (x[1] > 170 && x[1] < 1250 && y[1] > 150 && y[1] < 480) {lookzone<-1} if (x[1] > 170 && x[1] < 420 && y[1] > 480 && y[1] < 810) {lookzone <- 2} return(lookzone) }) however, when I run the function then nothing happens. and when I ask explicitly for the result then I get this > test NULL Can someone tell me what goes wrong here? Or give a hint? I'm not used to using the apply function and do use the for loop on the basis of an example that I once made so I am not a very experienced R user.. Thank you so much for your help! I really appreciate it! Bye,inga -- View this message in context: http://r.789695.n4.nabble.com/For-loop-with-i-and-j-and-multiple-if-statements-help-tp4646596p4646630.html Sent from the R help mailing list archive at Nabble.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.