using eplusr and coolprop to insert your weather data in EPW
The main.R call read_epw() function to parse the epw files provided by EnergyPlus and provide a way call CoolProp.dll to calculate the dew point temperature. Furthermore, you can organize your weather data in R. And write_epw()function allows you replace the epw files (including Location and Weather) with your own organized weather data.
By the way, both of read_epw() and write_epw() are programmed by Hongyuan Jia, a wise man :). You can find those amazing functions in the early version of eplusr. Unforunately, it seems that the express edition of eplusr remove the parts about editing epw files. Therefore, I just extract them from the forked version.