5
votes
2answers
59 views

How to select random adjacent census tract

I have set of census tracts spaced out across a city and I would like to randomly choose an adjacent census tract to explore nearby demographic data. I'm not sure if there is an easy process for ...
2
votes
2answers
60 views

How do I select Census Block Groups inside a Zip code?

Long time listener, first time caller. I already have my data imported, problem is my SELECT statements aren't yielding the results I'm looking for. I specifically need all the Block Group ...
6
votes
3answers
271 views

How can I obtain the same area values provided by the Census for TIGER boundaries using PostGIS functions?

In PostGIS, how can I compute the area of Census Boundaries and obtain the same results as are provided by the Census? For example, most Census Boundaries include attributes for Land Area and Water ...
3
votes
3answers
791 views

Best way to assign points to nearest roads in postgis?

I'm trying to implement a simplified type of dasymetric mapping for census data. I've downloaded the Census's American Community Survey individual-level data and randomly assigned every household to a ...
6
votes
2answers
689 views

PostGIS - area-weighted calculation on an intersection

I'm trying to learn postgis sql by performing some familiar operations from ArcGIS. Here, I want to perform an area-weighted calculation of certain populations on the intersection of a set of parcels ...
7
votes
2answers
2k views

What is the SRID of census.gov shapfiles?

I downloaded the county files from: http://www.census.gov/cgi-bin/geo/shapefiles2011/main I cannot figure out what SRID to use with them. When I am trying to generate a class file from ./manage.py ...