[GRASS-dev] bbox of a vector geometry

[Helmut Kudrnovsky]

Anna Petrášová wrote
> On Wed, Aug 10, 2016 at 2:01 PM, Helmut Kudrnovsky <

> hellik@

> > wrote:
>> hi devs,
>>
>> is there a way to get bboxes of vector geometries (polygones) in a vector
>> layer by pygrass/python grassscript and to loop through the bboxes?
> 
> 
> I would say, loop through the geometries and use .bbox():
> 
> https://grass.osgeo.org/grass70/manuals/libpython/pygrass.vector.html#pygrass.vector.geometry.Line.bbox

thanks!

after some poking around the programming manual and testing with the NC
sample dataset:

>>>from grass.pygrass.vector import VectorTopo
>>>from grass.pygrass.vector.geometry import Area
>>>lake = VectorTopo('lakes')
>>>lake.open(mode = 'r')

>>>lake.bbox()
Bbox(258302.909848, 196084.815242, 677118.419101, 610760.703857)

>>>lake.read(1)
LINEARRING (635797.5422910848900000 258138.3288798251600000,
635788.3098806196400000 258130.5942595548700000, 635783.6369824736600000
258136.4080263839000000, 635779.2935737869700000 258145.4350012375500000,
635776.6213868428000000 258154.4351536379500000, 635774.5834899671600000
258160.7990855638100000, 635770.6960629925600000 258166.9905003495200000,
635776.6043180087600000 258172.6283972222000000, 635782.4570993143100000
258168.6745237157400000, 635786.8794513597400000 258161.4946405562500000,
635790.4419608837900000 258153.9965455597800000, 635794.4360680728000000
258144.5449834555900000, 635797.5422910848900000 258138.3288798251600000)

>>>area1 = Area(v_id = 1, c_mapinfo = lake.c_mapinfo)

>>>area1.bbox()
Bbox(258172.628397, 258130.59426, 635797.542291, 635770.696063)

nice feature of pygrass!



-----
best regards
Helmut
--
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