I received an interesting brief this week at work: look into mapping our active members in order to get a better idea where in the city we need to promote more. Like anyone these days handed a mapping project, my first thought was “Google Maps!”.
However my previous experience working on the landmarks map made me a little wary in terms of gmaps’ ability to handle a large number of markers. Upon doing a little research, it became apparent that while gmaps does not itself impose a marker limit, the web browsers displaying the maps start to fall down at a certain point. It seems browsers start to fail to be able to render/manage markers at a point well below 5,000. With 43,000 active members, we had a problem.
Before giving up, it occurred to me that we didn’t really need a marker for every patron. What we really wanted to see was concentrations of patrons. A new google search turned up MapAList. This great, free tool generates google maps from lists of data uploaded to spreadsheets in google docs. One of their map types is a concentration map which generates a heatmap based on your data. This tool also handles the geocoding of street addresses for you.
As a test, I exported 5,000 random addresses from our ILS from one of the city’s six postal code prefixes. I imported the addresses into google docs and then let MapAList do its thing. It took maybe an hour to geocode the addresses. You can check out a screenshot of the resulting map below:
Well, I think I see an immediate use for that. If I have the data in a spreadsheet, I’ll bet I could map which parts of an area have more Democrats, Republicans and independents.
Yeah, it’s useful and easy. I’m guessing you’ll find some good uses for it!