topic Re: GWR data set limit in Spatial Statistics Questions

GWR data set limit

EveHalper — Thu, 23 Dec 2010 23:06:10 GMT

Is there a limit on the data set that can be used for a GWR regression? I would like to use a dataset with 27,000 points. The routine runs for a few seconds, says it is complete, but there are no results.

What is the largest data set that GWR can accomodate?

Thank you,

Eve Halper
Ph.D. Candidate
University of Arizona
halpere@email.arizona.edu

Re: GWR data set limit

LaurenRosenshein — Tue, 04 Jan 2011 22:12:41 GMT

Hi Eve,

I'm sorry to hear that you are having trouble running GWR on your dataset, and hopefully we can figure it out and get you moving forward quickly! You should not be having trouble running GWR on a dataset with 27,000 points. I just tried to reproduce the problem with a dataset with 30,000 points in 10 sp1 and had no trouble. So, let's try to figure out what is going on.

In order to move forward, can you please provide the following information:

--What version of ArcGIS are you using?

--What do you mean by "no results"? Are the results being created but not added to your table of contents? Are they not being created at all? Are they being saved to a valid path?

--What are the exact steps that you are taking when you run your analysis?

--Can you provide a screenshot of the Messages Window once GWR has executed sucessfully? Make sure that you run your analysis in the foreground if you want the messages window to appear when you are running GWR. Alternatively, you can right-click on the Messages from the Results window and choose to open them after the fact.

Again, I am very sorry that you are having trouble and I'm looking forward to working with you to get the problem resolved.

Lauren Rosenshein
Geoprocessing Product Engineer

Re: GWR data set limit

EveHalper — Tue, 04 Jan 2011 22:16:09 GMT

Thanks for your reply, Lauren.

I went back and read the help and found my problem was that I was using variables that were spatially autocorrelated. I was able to run the GWR with fewer variables.

Here's another question for you: Is there a way to generate a spatially lagged variable in ArcGIS the way you can in Geoda?

Thanks again,
Eve

Re: GWR data set limit

LaurenRosenshein — Wed, 05 Jan 2011 22:08:47 GMT

Hi Eve,

I'm glad to hear you got GWR working!

As far as the creation of a spatial lag variable, at this time we have not implemented this functionality in the Spatial Statistics toolbox. We have been working on a Sample Script (for the Geoprocessing Resource Center) that would create a spatial lag variable using R from within ArcGIS, but we are busy with 10.1 development and it may be a little while before that happens. If you are familiar with R, you may find this existing sample script useful as a template for leveraging R (the same way we are planning to in order to create spatial lag variables in the future).

You may also find this link valuable for additional resources on spatial statistics: http://bit.ly/spatialstats

Lauren