[Qgis-user] Random Points - Value from Input Field

[Alex Mandel]

On 02/23/2014 10:35 AM, Pete Cimbolic wrote:
> I am attempting to make a layer with one dot representing each person of a particular race using 2010 census data, similar to this one: http://demographics.coopercenter.org/DotMap/   
> 
> I am trying to figure out why I am able to do this using 2000 Census Tracts, but not 2010 Tracts.  I have joined demographic data to the shape files for both 2000 and 2010 tracts, formatted each the same way, yet when I try to select 2010 census tracts, no fields show up when I click on the “Use value from input field” toggle button under Vector>Research Tools>Random Points.  The fields do show up when I select the 2000 tracts.
> 
> Any thoughts?
> 
> Pete Cimbolic
> cimbolic at aclu-md.org
> 
Make sure QGIS is reading the fields in question as numeric or integer
and not as text. You can see this in the Properties of the layer, I
think under metadata. If it is reading it wrong, you'll need to check
that all the values are indeed numbers and either calculate a new field
based on it or edit the underlying format (I assume dbf) so that it is a
number.

Thanks,
Alex