[Qgis-user] FW: Using one vector layers to calculate the unemplyment rate in another vector layer

[Zirneklitis]

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.
> ..