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7/07/2020 8:35 pm  #1

Live Ferret city list doesn't always show my current city

When I open the Live Ferret map at my home in Boston, the first city that always loads is Brookline.  Then I open the list and scroll down through other cities; Milton, Cambridge, Newton, Dedham, Watertown, and then finally Boston.  It's a minor annoyance that my current city isn't first, but as a run farther from downtown the list changes and there are places where Boston doesn't show up at all, even though I'm still within city limits.

It feels like the list is sorted by the closest city, and that each city might be defined by a point that is not necessarily the geographical center.  In my case, Boston has an irregular shape and it's location seems to be defined somewhere downtown.  In the city's most southern neighborhoods (West Roxbury, Roslindale) Boston doesn't show up and I can't use the map.  Ideally the current city would always be first, but at a minimum it should show up in the list.  Could you take a look?


7/08/2020 11:19 am  #2

Re: Live Ferret city list doesn't always show my current city

Great bug report.  The "nearest" algorithm is based on the center point of the bounding box of each city.  This approach loads quickly and works great for cities and towns that are compact in shape but is terrible for places with odd shapes.  For Boston, the center point is a spot in Boston Harbor!  This approach sounded good on paper but clearly fails for real-world boundaries.

As a temporary hack, I moved the Boston center point to somewhere more reasonably central to the city.  So your pulldown should work for now.  This will get reset at some point when someone edits openstreetmap but it'll give me some time to figure out a proper fix involving a spatial index.


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