topic Re: Populating a field in a points layer with polygon number where the point is locat in Geoprocessing Questions

Populating a field in a points layer with polygon number where the point is located

JasonWinoker — Wed, 04 Aug 2010 18:29:11 GMT

I would like to populate a field which I added to a points layer with the number of a polygon layer in which the point is located. For example, the points are manholes in a County. The polygons are sections (with unique numbers). I would like to populate a field in the manholes layer with the appropriate number from the sections. I think that I will have to do a select by location-type operation, but I am unsure what to do from there. I am sure that there is a simple, but...

I appreciate your help/input.

Jason

Re: Populating a field in a points layer with polygon number where the point is locat

BBicking1 — Thu, 05 Aug 2010 16:24:37 GMT

I would like to populate a field which I added to a points layer with the number of a polygon layer in which the point is located. For example, the points are manholes in a County. The polygons are sections (with unique numbers). I would like to populate a field in the manholes layer with the appropriate number from the sections. I think that I will have to do a select by location-type operation, but I am unsure what to do from there. I am sure that there is a simple, but...

I appreciate your help/input.

Jason

Hi Jason,

see if this workflow in MBldr will get you what you want:

Intersect ManHoles points w/Section polies
AddField 'ManHoleInSection'
CalculateField ->in the expression you assign the section value from the field that holds it to the 'ManHoleInSection' field.

Barbara Bicking

Re: Populating a field in a points layer with polygon number where the point is locat

DanLee — Fri, 06 Aug 2010 20:17:41 GMT

You may also use Spatial Join tool (Analysis toolbox - Overlay toolset):
- Target Featueres = manholes
- Join Features = sections
- For the Field Map of Join Features, you can keep the fields you want from the sections and the manholes, and remove other fields.
- Match Option = INTERSECT

You should get a new output with the desired fields. Spatial Join tool combines the processes of selecting by location (you were on the right track), add field, and calculate field in one shot - a powerful tool!

Thanks.

Re: Populating a field in a points layer with polygon number where the point is locat

RickWahl — Tue, 10 Aug 2010 20:17:06 GMT

In a similar project, I've used a spatial join to a set of points where the polygon number matches what I want the point number to be 95% of the time. Because of this I need a script to assign the polygon number from the spatial join output points layer to a field on the original points attribute table.

I've joined the output of the spatial join to the original points layer. Does anyone have a good approach to a field calculate to assign the new number to the original field only if the original field is empty?