Area associated with thiessen polygons

[john singh]

Hello group,

I am new to geoda. And am trying to figure out something which should be simple.

I have a point emissions data from EPA. I created polygons associated with each point using the voronoi diagram/thiessen polygon functionality in geoda. 

Now I want to normalize the emissions from each point source with the associated area of the thiessen polygon. 

How do I get to the area of these polygons and add them to the table so that I can do this normalization? Unable to see any menu options which will show me to do that

Thank you so much!

John

[Julia Koschinsky]

Hi John,

Welcome! You're right that this is a standard GIS function -- GeoDa is designed as a supplement to GIS with a focus on spatial analytic functionality not typically found in a GIS, so calculating areas isn't included in GeoDa but you can do this in qGIS or any other GIS.

Best,

Julia

Julia Koschinsky, Ph.D.

Executive Director and Senior Research Associate

Center for Spatial Data Science

University of Chicago

https://spatial.uchicago.edu/

https://puttingscienceintodatascience.org/

---

From: openspa...@googlegroups.com <openspa...@googlegroups.com> on behalf of john singh <sing...@gmail.com>
Sent: Saturday, January 7, 2023 6:35 AM
To: openspa...@googlegroups.com <openspa...@googlegroups.com>
Subject: [Openspace] Area associated with thiessen polygons

 

--
You received this message because you are subscribed to the Google Groups "Openspace List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openspace-lis...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openspace-list/CAFJ0xByFJD%2BzbL8GXY%2BYV%2B%2BjHGUqB9%3DFvtF3qoFQ%3D69r1O%2BV4w%40mail.gmail.com.

[frankmhowell]

Hi John,

Try one of these methods:

https://www.northrivergeographic.com/qgis-calculating-an-area

The $area field is useful with appropriate project map units set. The Processing Toolbox also has several tools that might help you.

Frank

——

Frank M. Howell, PhD

Professor Emeritus, Mississippi State University

Ridgeland MS USA

[john singh]

Thank you Julia and Frank.

These comments help. 

I am beginning to understand the use cases for Geoda. I shouldn't think of Geoda as a one stop shop but to complement a GIS toolbox.

To view this discussion on the web visit https://groups.google.com/d/msgid/openspace-list/c049590e-65fb-4615-8b61-c8712075f9efn%40googlegroups.com.