In my pursuit of self learning the R programming language, I have mostly mastered the art of reading through CRAN documentation of R libraries as they are published. I have gone through everything from mediocre to very well documented sheets and anything in between. I am sharing one example of a very good function that was well documented in the 'survey' library by Dr. Thomas Lumley that for some reason I could not process and make work with my data initially. No finger pointing or anything like that here. It was merely my brain not readily able to wrap around the idea that the function passed another function in its arguments. fig1: the svyby function in the 'survey' library by Thomas Lumley filled in with variables for my study Readers familiar with base R will be reminded of another function that works similarly called the aggregate function, which is mirrored by the work of the svyby function, in that both call on data and both call on a function toward...