debug(FUN) then copy and paste an example from the help or create own example and run it; then step through the code, looking up unknown functions, exploring variations, looking at the effect of functions, etc.
getAnywhere(FUN) is important when the function is not exposed
Methods often require knowledge of S3 class conventions to discover e.g., print.default, print.lm rather than print
debug(FUN)then copy and paste an example from the help or create own example and run it; then step through the code, looking up unknown functions, exploring variations, looking at the effect of functions, etc.getAnywhere(FUN)is important when the function is not exposedprint.default,print.lmrather thanprint