I have a GPS dataset (lat/lon) and want to aggregate the data by zip code. In other words, I want to have a zip code map filled with the average of all data points that fall within each zip code boundary. How can I do that?
You would need to dowmload a shape map that has the polygon boundaries (latitude and longitude) for the zip files and create define the the shape and name file.
Per the USPS, zipcodes are frequently changed for efficiency. This link Discussion of 5 digit code zip file
This is another discussion https://www.reddit.com/r/gis/comments/8xe8l4/why_are_there_no_public_exhaustive_zip_code/
I believe the TIGER ZCTA file that some use is very large.
This is teh link to JMP documentation on Shape Files
See if this does what you need
Reverse Geocode Lat-Lon to Zip
Thank you, Craig. Your script posted at the link worked great.
I would likely never use zip code data unless I were restricting my graphs to a few counties, maybe a sparsely populated state.
This XY file I produced from your script has more detail than the US-County-XY.jmp file. But your script, provides a solution to producing a file of more detailed county shapes.
County Path has less detail