Hi, thanks for the hint. And if I need the value of the raster? If I understand correctly, ident will always be 1, if I have a 1 band raster layer. But how can I get the value at QgsPoint(x,y) of the raster? I don't understand that from the value tool plugin.
In QGIS 1.8 I use : success, data = layer.identify(QgsPoint(x,y)) for band, value in data.items(): return value and in QGIS 2.0: ident = layer.dataProvider().identify(QgsPoint(x,y),QgsRaster.IdentifyFormatValue).results() ? Thanks again Otto Am Fri, 2 Aug 2013 08:50:08 -0300 schrieb Etienne Tourigny <[email protected]>: > from the api > http://www.qgis.org/api/classQgsRasterIdentifyResult.html#a8537d25fdff215e7e9650b71a0a16783 > > results() returns a QMap<int, QVariant> (one item for each band), it > does not return a tuple, so you should actually call > > ident = > layer.dataProvider().identify(QgsPoint(x,y),QgsRaster.IdentifyFormatValue).results() > > and then test that ident is not empty (i,e. ident is not None and > ident.iterkeys() is not None) > > for each band, if the point is outside of the raster extent or is > nodata, the value will be a null QVariant (i.e. QVariant()) which in > python is None. > > > cheers > Etienne > > On Fri, Aug 2, 2013 at 7:13 AM, Otto Dassau <[email protected]> wrote: > > > > Hi, > > > > thanks for your hints, I think I am on the right track now. I had a look > > at the value tool plugin and tried to adapt the method accordingly: > > > > def sampleRaster20(self, layer, x, y): > > #success, data = layer.dataProvider().identify(QgsPoint(x,y)) > > success, data = > > layer.dataProvider().identify(QgsPoint(x,y),QgsRaster.IdentifyFormatValue).results() > > for band, value in data.items(): return value > > > > But now I get another error message > > > > File > > > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > line 448, in printValue self.showValues() File > > > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > line 454, in showValues self.plot() File > > > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > line 526, in plot w = > > float(self.sampleRaster(self.InRastW.currentText(), self.xCoord, > > self.yCoord))/10 File > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > line 300, in sampleRaster return self.sampleRaster20(layer, x, y) File > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > line 285, in sampleRaster20 success, data = > > layer.dataProvider().identify(QgsPoint(x,y), > > QgsRaster.IdentifyFormatValue ).results() ValueError: need more than 1 > > value to unpack > > > > Do you have an idea for this, too? > > > > Thanks > > Otto > > > > Am Thu, 1 Aug 2013 16:00:08 -0300 > > schrieb Etienne Tourigny <[email protected]>: > > > > > Have a look at the source of the value tool plugin, it calls the > > > identify() method and has been updated to 2.0 api. > > > > > > Etienne > > > > > > On Thu, Aug 1, 2013 at 1:58 PM, Otto Dassau <[email protected]> > > > wrote: > > > > > > > Hi, > > > > > > > > I want to update a plugin from 1.8 to QGIS 2.0 and it throws > > > > following error: > > > > > > > > Traceback (most recent call last): > > > > File > > > > > > > > > > > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > > > line 447, in printValue self.showValues() File > > > > > > > > > > > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > > > line 453, in showValues self.plot() File > > > > > > > > > > > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > > > line 514, in plot w = > > > > float(self.sampleRaster(self.InRastW.currentText(), self.xCoord, > > > > self.yCoord))/10 File > > > > > > > > > > > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > > > line 299, in sampleRaster return self.sampleRaster20(layer, x, y) > > > > File > > > > > > > > > > > > "/home/dassau/.qgis2/python/plugins/weibullanalyse/weibullanalysedialog.py", > > > > line 284, in sampleRaster20 success, data = > > > > layer.dataProvider().identify(QgsPoint(x,y)) > > > > > > > > TypeError: > > > > QgsRasterDataProvider.identify(QgsPoint, QgsRaster.IdentifyFormat, > > > > QgsRectangle theExtent=QgsRectangle(), int theWidth=0, int > > > > theHeight=0): not enough arguments > > > > > > > > I found at > > > > http://hub.qgis.org/wiki/quantum-gis/API_changes_for_version_20 the > > > > section QgsRasterDataProvider which should fit. And the Method, > > > > where I assume the error occurs should be this > > > > > > > > # get value at mouse position QGIS <= 1.8 (working for 1.8) > > > > def sampleRaster18(self, layer, x, y): > > > > success, data = layer.identify(QgsPoint(x,y)) > > > > for band, value in data.items(): > > > > return value > > > > > > > > now what I tried but doesn't work (see error above) > > > > > > > > # get value at mouse position QGIS >= 2.0 (not working yet :() > > > > def sampleRaster20(self, layer, x, y): > > > > success, data = layer.dataProvider().identify(QgsPoint(x,y)) > > > > for band, value in data.items(): > > > > return value > > > > > > > > my problem is, that I don't understand how to implement in > > > > sampleRaster20 the new method from the API_changes_for_version_20 > > > > website which says: > > > > > > > > QMap<int, QVariant> identify( const QgsPoint & thePoint, > > > > IdentifyFormat theFormat, const QgsRectangle &theExtent = > > > > QgsRectangle(), int theWidth = 0, int theHeight = 0 ) > > > > > > > > can anybody help? > > > > > > > > Thanks > > > > > > > > Otto > > > > _______________________________________________ > > > > Qgis-developer mailing list > > > > [email protected] > > > > http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > > > > > > > -- > > Geoinformatik Büro Dassau - http://www.gbd-consult.de > > FOSSGIS consulting , training , support and analysis > > Ackerstrasse 144c , D - 40233 Düsseldorf , Germany > > Tel: +49-(0)211-47468178 , Mobil: +49-(0)171-4687540 > > > > -- > > Community Advisor - QGIS Project Steering Committee -- Geoinformatik Büro Dassau - http://www.gbd-consult.de FOSSGIS consulting , training , support and analysis Ackerstrasse 144c , D - 40233 Düsseldorf , Germany Tel: +49-(0)211-47468178 , Mobil: +49-(0)171-4687540 -- Community Advisor - QGIS Project Steering Committee _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
