How to convert TIGER line file into

March 3, 2009 4:28 PM

Super-specific-GIS-filter: Converting TIGER/Line Files into a network of nodes and links?

Has anyone ever converted a TIGER file into a network matrix? I've done extensive googling on the topic and found one piece of java code, but could not get it to work as there were lots of errors, and I couldn't figure out what was wrong (it was also pretty old).

I'd appreciate hearing if anyone has done this or knows of a way to do so. I'm interested in converting TIGER to this format so that I can do some network analysis processing in matlab.

I'm fairly new to this type of analysis, so perhaps I'm missing something obvious. Thanks!

posted by a womble is an active kind of sloth to computers & internet (4 comments total)

TIGER format sucks. I recommend you use Open Street Map data, they've already exported all the TIGER data, and make it available for free in their OSM XML format, which sounds a lot like what you want. Basically each sampled point is available as a node which belongs to a feature of some kind (which has a unique ID), and you just scan through each feature, adding and linking each node in turn. Very easy. Better than TIGER. If you're comfortable doing network analysis I'm sure you won't have any trouble with this.
posted by doteatop at 4:36 PM on March 3

To give you an idea of the ease of parsing this format, here's a SAX parser for the OSM format, you can see this has a node list, and the addLink() method is called once for each pair of connected nodes.
posted by doteatop at 4:40 PM on March 3

Thank you doteatop - I'm having a look at the moment. My reason for considering TIGER is I was planning on trying to examine network patterns of cities. If I was to use openmap would I need to manually trace out each pattern?

Either way, this is really great - I'm glad to have learned about openmap.
posted by a womble is an active kind of sloth at 4:45 PM on March 3

Nope, you'd just need to select the specific features you want on the scale you want. They provide a lot of different means to access the data, you could just download all the US data in bulk and then only select out highways to get the connections between cities. It would be trivial also to programmatically select only highways which connect different cities, if connections between cities are all you are interested in.

Just noticed you tagged this question 'Java', I'm afraid I don't know any OSM parsers in Java but obviously writing your own SAX parser in Java is also easy.

I spent a while with the TIGER data tearing my hair out before I found out about OSM. Glad to have saved someone else the trouble.
posted by doteatop at 4:51 PM on March 3