[OSM-newbies] A square is a square is a square is a square .... (Was:Re: Entering building sizes in meters into one of the editors)

Tom Evans tom_evans_a at yahoo.co.uk
Thu Aug 14 19:54:49 BST 2008


2008/8/13 Norbert.J.Girardi <nobbes at girardis.de>:
> At lat='49.50218451651357' lon='8.604470651502528' I tried to draw a square
> of 20 by 20 meters as precisely as JOSM permitted.
>
> Have a look at what JOSM shows. This is not MY idea of a square ;-)
>
> Both, measurement plugin and the information line at the bottom of the JOSM
> screen agree that this "building" is 20x20 meters.

Your building is 20x20 meters (I just checked the maths, roughly, on
the coordinates in the osm file).  Unfortunately, it just doesn't
_look_ like it.  JOSM can use different projections for producing the
2D picture in front of you.  If you go to Edit -> Preferences and
switch it from 'EPSG:4326' to 'Mercator' and restart JOSM, it will
look more like your idea of a square.  It's the same shape on the
ground in both, but projected differently.

Unfortunately, I think EPSG is still the default due to some issues
with the WMS plugin in other projections.  Link below - somebody
please correct me if this isn't true anymore.
http://lists.openstreetmap.org/pipermail/josm-dev/2007-November/000419.html

Tom




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