I am running Geographically Weighted Regression and originally was using ArcGIS to carry out the analysis until I read/heard mixed reviews about it. I have now tried a different programme to run it (SAM) and get different results.
Does anyone know what the spatial weighting function is in ArcGIS? I think it is Gaussian but am not 100% sure. I cannot select this with Arc but there are different options to chose from with SAM.
Thanks!
The ArcGIS online help page has the answer here: http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=How%20GWR%20Regression%20works
In particular this quote seems particularly pertinent:
Parameter estimates and predicted values for GWR are computed using the following spatial weighting function: exp(-d^2/b^2). There may be differences in this weighting function among various GWR software implementations. Consequently, results from the ESRI GWR tool may not match results of other GWR software packages exactly.
