[Openspace] problem with converting to rates

[Jochen Mistelbacher]

Hi Kim,

though this method should be used only with phenomena that change 
continously across space, Tobler`s "Pycnophylactic Interpolation" could 
be used as well. There is a script available for ArcView, don`t know if 
it works in ArcGIS as well.

http://arcscripts.esri.com/details.asp?dbid=10918

I used it for the same kind of problem. There should be some papers 
available online describing the method. Basically its a great tool for 
areal interpolation of polygon-data.

Greetings,

Jochen Mistelbacher

Dept. of Economic Geography
University of Mannheim
Germany




Lersch, Kim (USF Lakeland) wrote:

> Hello all:  I am new to the listserve and GeoDa.  I'm really 
> struggling with a data management issue and hope that someone out 
> there can provide me some guidance.  My thanks in advance for your time. 
>  
> I have a dataset that contains the location of use of force incidents 
> by a police agency.  I am going to convert the number of incidents to 
> a rate based on the block group census data population values.  This 
> is easy enough.  Where things get tricky is I also wish to consider 
> the neighborhood crime rate where the police used force.  I have data 
> from the police agency that includes the number of crimes that 
> occurred in a crime tract which, of course, is a different area than a 
> census tract / block.  Is there a way that I can estimate the number 
> of residents who reside in a crime tract even though the polygons do 
> not match up?  Is there a generally accepted way of doing this?  The 
> census blocks are smaller than the crime tracts.  
>  
> I'd appreciate any suggestions on this matter.  I am using ArcGIS as 
> well as GeoDa.
>  
> Best,
>  
> Kim Lersch
> Department of Criminology
> University of South Florida 
>
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