Oh those wacky geolocations.

So, yesterday I spent some time working up a nifty little display to make sure all the counties were showing up the way I needed them to.

I found out that most (about 45) of the counties in Colorado, actually showed up in Colorado... and some of them were showing up in other states.

Because I made a very naive assumption that County Names did not repeat in the US. And, like that assumption that birthdays don't cluster, it came as a nasty surprise. Thankfully, because I made sure to maintain the poicondai-loader project the way I did, it only took me the better part of an evening to change the loading scheme so that it supported county, state, and geolocation data.

The rest of today has been spent setting up some utility classes for pulling what I am calling PoiConCounts. I spent a lot of thought-chewing time figuring out the granularity of the objects for optimal caching and pulling (and many thanks to Brian for busting me out of the loop I was finding myself in) and just settled on "the thing that is going to be displayed". I have made this flexible, in case the way things need to be displayed or stored ever changes.

Tomorrow I will be trying to get that first county yank into a map with appropriate shading. If that goes well I will probably be ambivalent about whether to try and get the histogram-popup working or move on to zipcodes. But let's not fillet those fish yet...

RODS, poicondai-web, and GIS.

Yesterday I got the filtering completed... today I started answering the question "so how do you get google maps to show polygons for zip codes" and I learned quite a few things.

1. Lots of other people have done this before me, as there are all sorts of cool websites (with code access for pay) that have the overlays for zip codes and phone area codes on top of a google map.
   
2. Lots of these sites seem to work by building a KML that google can read.
   
3. RODS is one of these sites, and at least that code is free.

What I am trying to do will use KML as a last resort. KML generation means you have to stick a KML document at some public URL and tell google maps to find it, and the CDC end of the grid is all sorts of locked down... and as far as I can tell, Google Maps regrettably does not have a "send me a string of KML" function.

But, there are ways to generate polygons and overlays with just the javascript commands, just like there are ways to drop points on a map with javascript commands, it's just a matter of teasing out coordinates for the borders of the polygons, and Jeremy helped me discover the appropriate PostGIS and postgres tools that are supposed to let me get a zip-code/border database... and he has shown me the way to the RODS code that makes the appropriate queries to get the coordinates that are usually sent to KML. I'll just have to make it so they are sent to javascript arrays instead.

It'll be a bit kludgey, and will probably need some caching, but it should work, and then you know the only thing you need to see to deploy the POIConDai web visualization is access to the service and the appropriate GIS database.

Also, tomorrow will probably be spent focusing on just getting the zip code centroids working and teasing the data out of the NPDS service appropriately. But it's nice to have some part of my mind working on how to turn those dots into polygons for the time being.

Otherwise, we had a meeting with the ESRI/DGI-net guys. Their browser is mega-posh.