skip if file or model exists in loop

Question

I am working on making a loop in R that creates species distribution models in R for multiple species in a relatively large matrix. In order to avoid analysis redundancy, I would like to have a command at the beginning of the loop to skip the analysis if a file output already exists. Does anyone have any suggestions on how to add this line of code?

Answer 1

if(file.exists(filename)) {
   next
}

at the beginning of the loop? As long as you really wish not only to use a loop in R but also a next in there :)