LA.pm: Re: phl.pm map

[Robert Spier]

Joe Smith writes:
>Hi Rob, this is cool.  I've been looking for a way to generate this kind of 
>map to do some simple demographics.  It might involve 150-200 locations and 
>circles from a fixed location (e.g. within 3 miles).  Can Tiger do this?  
>Could you post a note to the list that outlines how you create the map?  As 
>far as I can tell, the Tiger map generator only does one point (or one at a 
>time at least).

Joe asked how I generate the map, so here's brief answer:

1. Drop data into a file that looks something like this:

# Robert
home: 34.186238  118.300898
work: 34.171746  118.323148 
# etc...

2. Run simple perl script to convert it into tiger format, which looks
   like this.

#tms-data
-118.300898,34.186238:bludot10:
-118.323148,34.171746:reddot10:

   This is what lets me put multiple points on the map.  It's
   documented in the instructions document, which is a little hard to
   find.

    http://tiger.census.gov/instruct.html#MURL

3. Go to tiger web page, tell it the URL of the file generated in step
   2.  Tweak settings of position, scale, size, etc.

4. Save generated .gif file and put on web somewhere.

It's really that simple.  

Joe- as for your specific question about circles, I don't think it's
possible - but, you could probably make circles with a little bit of
math and some small dots, or just draw them on afterwards :)

One thing to remember about Tiger, is a) it's free, and b) it's mostly
unsupported.  It was an experiment, that thankfully (Thanks Lisa's
coworkers!) they've kept running.

-R