Sorry for bothering everyone.

I am not too sure why the summary statistics of r_ga and insideGARnFile_WithCoord) are different, but the output graphics looked very similar. I will assume slight boundary mismatch is due to coordinate reference system (difference/transformation). I will assume the problem is solved for now. If you have any insights on the boundary mismatch, please leave your comments here.

Much appreciated! Summary statistics of insideGARnFile_WithCoord Rainfall Output from insideGARnFile_WithCoord

Summary statistics of r_ga. Rainfall Output from r_ga

dchan