Hi, Just an idea:
1. Using the Field calculator add a new column with polygon areas for the police district layer.
2. Create the third layer as an intersection between the Sensus sub-place layer and the police district layer.
3. Using the Field calculator add a new column with polygon areas. Now you have a attribute table to calculate the statistics.
Best regards, Karlis Pretorius Deon - Lieutenant Colonel wrote:
.. I have a vector layer that exist out of about 1000 polygons of the different police districts. Then I have a Sensus sub-place vector layer with over 10 000 sub-places which indicate the number of unemployed citizens per polygon. The Sensus sub-place layer therefor overlaps with the police districts and when visualize some sub-places can make up 1% up to 100% of a given police district. Most of the police districts also contains 4 or more sub-places. The problem is I want to calculate the ”approximate” unemployment rate per police district by using the data from the Sensus sub-place layer. Is there perhaps an explanation on how I can determine” approximately proportionally” what the unemployment is per police district. I am new to QGIS and not up to date with programming, however any assistance would be appreciated. ..
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