Now plotting retained % over 30-day periods
Rolled back active.R to previous version; script for the 30-day periods data now is active_30.R
Checking for strata, added surv2df utility function to ggsurv.R
Updated spreadsheet with results of email registration; added spreadsheet with comparison of results from observational study
Accouting for shrinking sample size in tail of long-term retention data; added plot of effect size over time
Added stub for importing person-period dataset
Merge branch 'master' of github.com:junkieDolphin/MoodBar