topic Re: Can you use a polygon dataset when creating a O-D Matrix? in ArcGIS Network Analyst Questions

Can you use a polygon dataset when creating a O-D Matrix?

PhilBragas — Thu, 15 Jan 2015 01:24:29 GMT

hello,

I've been using the O-D Cost Matrix in ARCGIS 10.2.2 successfully when I load both origins and destination as point datasets.

Previously, when I have a polygon feature class I just calculate the centroid x and y coordinates and convert this to point dataset. This has worked well for some projects I have done.

I have been asked to do an O-D cost matrix for a School's point dataset and a Parks polygon feature. I could create a centroid point from the Parks polygon feature but some parks are very large and the centroid point within suck parks will give misleading distances.

I was wondering if there was a way to do an O-D Matrix with the Schools points dataset that would create lines to the closest edge of a Parks polygon feature?

Please let me know if this is possible?

Thanks

Re: Can you use a polygon dataset when creating a O-D Matrix?

MelindaMorang — Thu, 15 Jan 2015 16:47:34 GMT

Hi. Since the OD Cost Matrix tool requires points as input, you will have to figure out some way of converting the parks into points. Since the centroids aren't adequate in this case, you need to find a better way of representing the parks.

If you know where the park entrances are (assuming there are official "entrances), you could manually create points at the entrances, and use those as your OD input.

If the parks can be entered from anywhere, you might try using street intersections within a certain small buffer around the park feature. So, take your street junctions feature class and select by location for the junctions that fall within 10 meters (or whatever distance makes sense) of your park polygons. Export those selected junctions as a park point feature class and use that as the input.

Re: Can you use a polygon dataset when creating a O-D Matrix?

PhilBragas — Mon, 19 Jan 2015 00:29:06 GMT

Thanks Melinda,

Sounds like a good way around the problem. I will try initially with using the buffer to collect intersections whixch are relevant to each park and go from there.

thanks again,

Phil