topic I have multiple points with city names, how do i combine them to my polygons? in Data Management Questions

I have multiple points with city names, how do i combine them to my polygons?

JohnNovi — Mon, 13 May 2013 20:39:42 GMT

I have a shapefile of LA county with a single polygon for each city. I also have a table with x,y data that has been represented and the city names for each event match with the city names for the polygons. So how can I combine the point data to the polygons to do polygon analysis?

Trying to join doesn't work since there are several events for each city and only one input for each city

Re: I have multiple points with city names, how do i combine them to my polygons?

JoeBorgione — Tue, 14 May 2013 10:44:03 GMT

I have a shapefile of LA county with a single polygon for each city. I also have a table with x,y data that has been represented and the city names for each event match with the city names for the polygons. So how can I combine the point data to the polygons to do polygon analysis?

Trying to join doesn't work since there are several events for each city and only one input for each city

Are you trying a tabular join or a spatial join? Your post is a bit confusing. Try these steps:

add your xy data as an event
export the event data to a point feature class
be sure to add the newly created feature class ( you may want to remove the event)
right click on your polygon feature class and select join
you are given several options of what you want to track in the resulting polygons

What exactly is the polygon analysis you are trying to accomplish?

Re: I have multiple points with city names, how do i combine them to my polygons?

RobertBorchert — Tue, 14 May 2013 11:44:39 GMT

Export your events as a shaprefile first or to a database

I have a shapefile of LA county with a single polygon for each city. I also have a table with x,y data that has been represented and the city names for each event match with the city names for the polygons. So how can I combine the point data to the polygons to do polygon analysis?

Trying to join doesn't work since there are several events for each city and only one input for each city

Re: I have multiple points with city names, how do i combine them to my polygons?

JohnNovi — Tue, 14 May 2013 13:22:18 GMT

so for more info what I'm trying to do is I have a spreadsheet of all the crimes that occurred in LA county over a 30 day period with x,y data. I also have a shapefile that has individual polygons for each of the cities in LA county. The crimes spreadsheet contains the city names as well. I wanted to sort of join or relate the crimes data to the polygons to do some analysis such as which cities are drug crimes more prevalent, what city is most likely to get your car stolen etc. simple stuff since this is only for a class project.

I know how to do the analysis I just am racking my brain trying to figure out a way apply like 50-500+ incidents (10k crimes in 1 month for LA county) all with the same city name to a single polygon with the same name so then I can run analysis on the polygons

Re: I have multiple points with city names, how do i combine them to my polygons?

JoeBorgione — Tue, 14 May 2013 14:09:44 GMT

I think you'll want to use a relate or relationship class as a 1(polygon) to Many (crime incidents).

First and foremost I reccomend getting the data out of a spreadsheet and into a geodatabase table. Spreadsheets are okay.... If you are doing your taxes...

As long as your city codes have a consistent value [that is, spelled the same way] between the polygons and incident data, use it with which to create the relationship.

You can use a Many to One join; but that may be a little cumbersome if you are planning to map the data.