<div dir="ltr">Hi all,<div><br></div><div>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:</div><div><br></div><div>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.</div>
<div>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.</div>
<div><br></div><div>The second thing is about projection. For this projection:</div><div><br></div><div><div>name=Lambert Conformal Conic</div><div>proj=lcc</div><div>datum=nad83</div><div>a=6378137.0</div><div>es=0.006694380022900787</div>
<div>lat_1=34.33333333333334</div><div>lat_2=36.16666666666666</div><div>lat_0=33.75</div><div>lon_0=-79</div><div>x_0=609601.2199999997</div><div>y_0=0</div><div>no_defs=defined</div><div>unit=Foot_US</div><div>units=Foot_USs</div>
<div>meters=0.3048006096012192</div></div><div><br></div><div>I get nothing from m.measure. I can create a ticket if necessary.</div><div><br></div><div>Best,</div><div><br></div><div>Anna<br><div class="gmail_extra"><br>
<br><div class="gmail_quote">On Mon, Dec 30, 2013 at 7:50 AM, Markus Neteler <span dir="ltr"><<a href="mailto:neteler@osgeo.org" target="_blank">neteler@osgeo.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div class="im">On Sat, Dec 28, 2013 at 3:28 PM, Vincent Bain <<a href="mailto:bain@toraval.fr">bain@toraval.fr</a>> wrote:<br>
> Hello dear devs,<br>
><br>
> I am wondering if something happened since this 4 year old ticket, where<br>
> the question of area measurements was raised :<br>
><br>
> <a href="http://trac.osgeo.org/grass/ticket/975" target="_blank">http://trac.osgeo.org/grass/ticket/975</a><br>
><br>
> When I need to get an area on the fly, I run d.measure on a graphic<br>
> monitor, but it would be very nice to access this function straightly<br>
> from wxGUI. Using 6.4 for my workflow, perhaps I missed something on the<br>
> 7.0 side ?<br>
<br>
</div>In the ticket m.measure is suggested as solution which accepts a<br>
series of coordinates to then perform the calculation:<br>
<a href="http://grass.osgeo.org/grass70/manuals/m.measure.html" target="_blank">http://grass.osgeo.org/grass70/manuals/m.measure.html</a><br>
<br>
Perhaps, given that a new tiny digitizer is there for wxGUI-i.class<br>
etc, perhaps this could be used to call m.measure then?<br>
<div class="im"><br>
> Thank you, and best wishes for New Year's Eve ;-)<br>
<br>
</div>Thanks & best wishes from here,<br>
Markus<br>
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