Hi all, I added support for area measurement in wxGUI (the same place as measuring distance). You are welcome to test. However, I have a few questions/problems:
I was wondering if module m.measure requires a series of coordinates with or without repeating the first pair of coordinates. This is suggested by the fact that it requires at least 4 points for measuring area. If I suppress this condition and use only 3 points it gives me the right result, too. This is probably given by the underlying functions G_area_of_polygon, but I haven't found anything in the documentation. I would be glad if we can write something in the m.measure manual because the user might be surprised not to get area for 3 points. The second thing is about projection. For this projection: name=Lambert Conformal Conic proj=lcc datum=nad83 a=6378137.0 es=0.006694380022900787 lat_1=34.33333333333334 lat_2=36.16666666666666 lat_0=33.75 lon_0=-79 x_0=609601.2199999997 y_0=0 no_defs=defined unit=Foot_US units=Foot_USs meters=0.3048006096012192 I get nothing from m.measure. I can create a ticket if necessary. Best, Anna On Mon, Dec 30, 2013 at 7:50 AM, Markus Neteler <[email protected]> wrote: > On Sat, Dec 28, 2013 at 3:28 PM, Vincent Bain <[email protected]> wrote: > > Hello dear devs, > > > > I am wondering if something happened since this 4 year old ticket, where > > the question of area measurements was raised : > > > > http://trac.osgeo.org/grass/ticket/975 > > > > When I need to get an area on the fly, I run d.measure on a graphic > > monitor, but it would be very nice to access this function straightly > > from wxGUI. Using 6.4 for my workflow, perhaps I missed something on the > > 7.0 side ? > > In the ticket m.measure is suggested as solution which accepts a > series of coordinates to then perform the calculation: > http://grass.osgeo.org/grass70/manuals/m.measure.html > > Perhaps, given that a new tiny digitizer is there for wxGUI-i.class > etc, perhaps this could be used to call m.measure then? > > > Thank you, and best wishes for New Year's Eve ;-) > > Thanks & best wishes from here, > Markus > _______________________________________________ > grass-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-dev >
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