ProjectGuidelines.md

This document is a collection of guidelines, practices & patterns that I'd like for us to be consistent about for the code in our projects.

Variables

1. Missing values in a continuous variable should be represented as NA. {Oct 28, 2012}
2. Missing values in factor variables should be represented as another level called 'Unknown' (eg, ds$sex <- factor(ds$sex, levels=0:2, labels=c("Female", "Male", "Unknown"))). There should be no NA values remaining in a factor variable. Assign them to a level like ds$sex[is.na(ds$sex)] <- "Unknown" {Oct 28, 2012}

Variable Naming

1. When the REDCap database has already established a name, try to follow that style. {Oct 28, 2012}
2. When possible use no underscores, and capitalize the first letter of each word (eg, RaceBlack, RaceWhite.) {Oct 28, 2012}
3. REDCap doesn't allow uppercase letters in its variable names, so maybe we should adopt the all_lowercase_letters_separated_by_underscores. {Added July 21, 2013}
4. Acronyms that are three or more letters are capitalized like a real word (eg, GedMale, HSDiplomaMale) {Oct 28, 2012}