I'm working in ArcMap 10 and can move around in R, though am not an expert.
I have a shp file and an xlsx file. The shp file is 20,221 rows and includes a field GID (grid ID) which is not unique among rows because multiple polygons named with a PID (park ID) can have the same GID. PID-GID pairs are unique.
The xlsx file 230,895 rows and also has a GID field which is not unique among rows because for each GID there are 60 years worth of data, each year represented by a row. Year-GID pairs are unique.
How can I combine the two files so that for each PID-GID combo in the shp file I get a row for each GID-year combo in the xlsx file?
I've been playing with joins and query tables and can't get it yet. Much thanks.