search for: tl_2009_12_zcta3

I have four files that map populations to appropriate keys: statepop.csv, countypop.csv, zip3.csv, and zip5.csv. I'm using the TIGER/Lines shape files: tl_2009_12_state, tl_2009_12_county tl_2009_12_zcta3, and  tl_2009_12_zcta5. I have carefully followed a number of tutorials and can reproduce those, and can also produce scatter and bubble plots of my data (using long and lat coordinates to place the pch and bubbles). What the tutorials (apparently) don't cover is how to key the data with the s...