On Fri, Aug 2, 2013 at 11:58 AM, Otto Dassau <das...@gbd-consult.de> wrote: > 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.
no, ident will be a dict with an element of key 1 you get exactly the fist band's value at the point with ident[1] . the key of the map is the band number, and the value is the value (or None if nodata/out of bounds) so without any error checking you would do ident = layer.dataProvider().identify(QgsPoint(x,y),QgsRaster.IdentifyFormatValue).results() return ident[1] cheers Etienne > > 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 <etourigny....@gmail.com>: > >> 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 <das...@gbd-consult.de> 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 <etourigny....@gmail.com>: >> > >> > > 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 <das...@gbd-consult.de> >> > > 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 >> > > > Qgis-developer@lists.osgeo.org >> > > > 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 Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer