Re: [Qgis-developer] How to get feat.geometry() from SpatiaLite in pyQGis ?

2013-12-06 Thread Geo DrinX 
Hi Christos (!),


sorry but your code works only in QGis 1.8 version.
I am using the 2.0.1 version and pyQGis methods are changed:

http://hub.qgis.org/wiki/quantum-gis/Python_plugin_API_changes_from_18_to_20


BTW, my problem is:

- using a SHP file layer,  elements are returned
- using SpatiaLite layer,  elements are returned, but each is empty.


It 'a known issue?
Someone in the list has tried it?


Roberto


2013/12/6 mmekuria 

> Hi, Roberto:
>
> I think the query from layer.getFeatures() returns an iterator and that
> means you use the nextFeature(feat) to get the next feature until it fails
> to return a feature, then it means you have reached the end of the iterator
> list.
>
> iter = layer.getFeatures()
> while iter.nextFeature(feat):
> geom = feat.geometry()
> elem = geom.asPolyline()
> print("ELEM %s\n") %(elem)
> for p1 in elem:
> x1,y1 = p1.x(),p1.y()
> print("XY= %lf %lf\n") %(x1, y1)
>
>
> Should work for you,
>
>
>
>
>
> -
> Maaza Christos, PhD
> www.Axumcorp.com
>
> --
> View this message in context:
> http://osgeo-org.1560.x6.nabble.com/How-to-get-feat-geometry-from-SpatiaLite-in-pyQGis-tp5092891p5093041.html
> Sent from the Quantum GIS - Developer mailing list archive at Nabble.com.
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Re: [Qgis-developer] How to get feat.geometry() from SpatiaLite in pyQGis ?

2013-12-06 Thread giulianc51 
Il giorno Thu, 5 Dec 2013 11:10:03 +0100
Geo DrinX  ha scritto:

> Hello all,

Hi Roberto (sorry for my bad english :-)

> as in object, within pyQGis  I need to read the geometry of a
> SpatiaLite vector layer.
> 
> This is my source code:
> 
> layer = iface.mapCanvas().currentLayer()
> iter = layer.getFeatures()
> for feat in iter:
> geom = feat.geometry()
> elem = geom.asPolyline()
> print("ELEM %s\n") %(elem)
> for p1 in elem:
> x1,y1 = p1.x(),p1.y()
> print("XY= %lf %lf\n") %(x1, y1)
> 
> 
> But... it returns only:
> 
> ELEM []
> ELEM []
> ELEM []
> ELEM []
> .
> Somebody can help me to understand how to get geometry from
> SpatiaLite ?
> 

I tried in python console on a Spatialite linestring layer:
cLayer=iface.activeLayer()
iter=cLayer.getFeatures()
feat=iter.next()
geom=feat.geometry()
ln=geom.asPolyline()
pnt=ln[0]
print pnt.x(),pnt.y()
with the correct answer:
1511590.31375 5099925.78455
(but I'm on a old 1.9.0-Master)


> Thank you in advance
> 
> Roberto

bye,
giuliano

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Re: [Qgis-developer] How to get feat.geometry() from SpatiaLite in pyQGis ?

2013-12-05 Thread mmekuria 
Hi, Roberto:

I think the query from layer.getFeatures() returns an iterator and that
means you use the nextFeature(feat) to get the next feature until it fails
to return a feature, then it means you have reached the end of the iterator
list.

iter = layer.getFeatures()
while iter.nextFeature(feat):
geom = feat.geometry()
elem = geom.asPolyline()
print("ELEM %s\n") %(elem)
for p1 in elem:
x1,y1 = p1.x(),p1.y()
print("XY= %lf %lf\n") %(x1, y1) 


Should work for you,





-
Maaza Christos, PhD
www.Axumcorp.com

--
View this message in context: 
http://osgeo-org.1560.x6.nabble.com/How-to-get-feat-geometry-from-SpatiaLite-in-pyQGis-tp5092891p5093041.html
Sent from the Quantum GIS - Developer mailing list archive at Nabble.com.
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[Qgis-developer] How to get feat.geometry() from SpatiaLite in pyQGis ?

2013-12-05 Thread Geo DrinX 
Hello all,


as in object, within pyQGis  I need to read the geometry of a SpatiaLite
vector layer.

This is my source code:

layer = iface.mapCanvas().currentLayer()
iter = layer.getFeatures()
for feat in iter:
geom = feat.geometry()
elem = geom.asPolyline()
print("ELEM %s\n") %(elem)
for p1 in elem:
x1,y1 = p1.x(),p1.y()
print("XY= %lf %lf\n") %(x1, y1)


But... it returns only:

ELEM []
ELEM []
ELEM []
ELEM []

etcetera, instead of something like this :

ELEM [(2.37786e+06,4.60302e+06), (2.37784e+06,4.60304e+06)]

... that I had with a "normal" qgis layer.

Sure, I miss something.

Somebody can help me to understand how to get geometry from SpatiaLite ?


Thank you in advance

Roberto
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