def testSimplifyIssue4189(self):
"""Test we can simplify a complex geometry.
Note: there is a ticket related to this issue here:
http://hub.qgis.org/issues/4189
Backstory: Ole Nielson pointed out an issue to me
(Tim Sutton) where simplify ftools was dropping
features. This test replicates that issues.
Interestingly we could replicate the issue in PostGIS too:
- doing straight simplify returned no feature
- transforming to UTM49, then simplify with e.g. 200 threshold is ok
- as above with 500 threshold drops the feature
pgsql2shp -f /tmp/dissolve500.shp gis 'select *,
transform(simplify(transform(geom,32649),500), 4326) as
simplegeom from dissolve;'
"""
myWKTFile = file(
os.path.join(unitTestDataPath('wkt'), 'simplify_error.wkt'), 'rt')
myWKT = myWKTFile.readline()
myWKTFile.close()
print myWKT
myGeometry = QgsGeometry().fromWkt(myWKT)
assert myGeometry is not None
myStartLength = len(myWKT)
myTolerance = 0.00001
mySimpleGeometry = myGeometry.simplify(myTolerance)
myEndLength = len(mySimpleGeometry.exportToWkt())
myMessage = 'Before simplify: %i\nAfter simplify: %i\n : Tolerance %e' % (
myStartLength, myEndLength, myTolerance)
myMinimumLength = len('POLYGON(())')
assert myEndLength > myMinimumLength, myMessage
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT))
tolerance = self.getParameterValue(self.TOLERANCE)
pointsBefore = 0
pointsAfter = 0
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
layer.pendingFields().toList(), layer.wkbType(), layer.crs())
features = vector.features(layer)
total = 100.0 / len(features)
for current, f in enumerate(features):
featGeometry = QgsGeometry(f.geometry())
attrs = f.attributes()
pointsBefore += self.geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(tolerance)
pointsAfter += self.geomVertexCount(newGeometry)
feature = QgsFeature()
feature.setGeometry(newGeometry)
feature.setAttributes(attrs)
writer.addFeature(feature)
progress.setPercentage(int(current * total))
del writer
ProcessingLog.addToLog(ProcessingLog.LOG_INFO,
self.tr('Simplify: Input geometries have been simplified from %s to %s points' % (pointsBefore, pointsAfter)))
def testSimplifyIssue4189(self):
"""Test we can simplify a complex geometry.
Note: there is a ticket related to this issue here:
http://hub.qgis.org/issues/4189
Backstory: Ole Nielson pointed out an issue to me
(Tim Sutton) where simplify ftools was dropping
features. This test replicates that issues.
Interestingly we could replicate the issue in PostGIS too:
- doing straight simplify returned no feature
- transforming to UTM49, then simplify with e.g. 200 threshold is ok
- as above with 500 threshold drops the feature
pgsql2shp -f /tmp/dissolve500.shp gis 'select *,
transform(simplify(transform(geom,32649),500), 4326) as
simplegeom from dissolve;'
"""
myWKTFile = file(os.path.join(unitTestDataPath('wkt'),
'simplify_error.wkt'), 'rt')
myWKT = myWKTFile.readline()
myWKTFile.close()
print myWKT
myGeometry = QgsGeometry().fromWkt(myWKT)
assert myGeometry is not None
myStartLength = len(myWKT)
myTolerance = 0.00001
mySimpleGeometry = myGeometry.simplify(myTolerance)
myEndLength = len(mySimpleGeometry.exportToWkt())
myMessage = 'Before simplify: %i\nAfter simplify: %i\n : Tolerance %e' % (
myStartLength, myEndLength, myTolerance)
myMinimumLength = len('POLYGON(())')
assert myEndLength > myMinimumLength, myMessage
def processAlgorithm(self, layer, tolerance, layerName):
writer = QgsVectorLayer("Polygon?crs=EPSG:2180", layerName, "memory")
writer.startEditing()
pointsBefore = 0
pointsAfter = 0
features = vector.features(layer)
for current, f in enumerate(features):
featGeometry = QgsGeometry(f.geometry())
pointsBefore += self.geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(tolerance)
pointsAfter += self.geomVertexCount(newGeometry)
feature = QgsFeature()
feature.setGeometry(newGeometry)
writer.addFeature(feature)
writer.commitChanges()
return writer
ProcessingLog.addToLog(ProcessingLog.LOG_INFO,
self.tr('Simplify: Input geometries have been simplified from %s to %s points' % (pointsBefore, pointsAfter)))
def processAlgorithm(self, layer, tolerance, layerName):
writer = QgsVectorLayer("Polygon?crs=EPSG:2180", layerName, "memory")
writer.startEditing()
pointsBefore = 0
pointsAfter = 0
features = vector.features(layer)
for current, f in enumerate(features):
featGeometry = QgsGeometry(f.geometry())
pointsBefore += self.geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(tolerance)
pointsAfter += self.geomVertexCount(newGeometry)
feature = QgsFeature()
feature.setGeometry(newGeometry)
writer.addFeature(feature)
writer.commitChanges()
return writer
ProcessingLog.addToLog(
ProcessingLog.LOG_INFO,
self.
tr('Simplify: Input geometries have been simplified from %s to %s points'
% (pointsBefore, pointsAfter)))
def runSimplify(self):
self.mutex.lock()
self.stopMe = 0
self.mutex.unlock()
interrupted = False
shapeFileWriter = None
pointsBefore = 0
pointsAfter = 0
if self.writeShape:
vProvider = self.inputLayer.dataProvider()
shapeFields = vProvider.fields()
crs = vProvider.crs()
wkbType = self.inputLayer.wkbType()
if not crs.isValid():
crs = None
shapeFileWriter = QgsVectorFileWriter(self.outputFileName, self.outputEncoding, shapeFields, wkbType, crs)
featureId = 0
if self.useSelection:
selection = self.inputLayer.selectedFeatures()
self.emit(SIGNAL("rangeCalculated( PyQt_PyObject )"), len(selection))
for f in selection:
featGeometry = QgsGeometry(f.geometry())
attrMap = f.attributes()
pointsBefore += geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(self.tolerance)
pointsAfter += geomVertexCount(newGeometry)
feature = QgsFeature()
feature.setGeometry(newGeometry)
feature.setAttributes(attrMap)
shapeFileWriter.addFeature(feature)
featureId += 1
self.emit(SIGNAL("featureProcessed()"))
self.mutex.lock()
s = self.stopMe
self.mutex.unlock()
if s == 1:
interrupted = True
break
else:
self.emit(SIGNAL("rangeCalculated( PyQt_PyObject )"), vProvider.featureCount())
f = QgsFeature()
fit = vProvider.getFeatures()
while fit.nextFeature(f):
featGeometry = QgsGeometry(f.geometry())
attrMap = f.attributes()
pointsBefore += geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(self.tolerance)
pointsAfter += geomVertexCount(newGeometry)
feature = QgsFeature()
feature.setGeometry(newGeometry)
feature.setAttributes(attrMap)
shapeFileWriter.addFeature(feature)
featureId += 1
self.emit(SIGNAL("featureProcessed()"))
self.mutex.lock()
s = self.stopMe
self.mutex.unlock()
if s == 1:
interrupted = True
break
else: # modify existing shapefile
if not self.inputLayer.isEditable():
self.inputLayer.startEditing()
self.inputLayer.beginEditCommand("Simplify line(s)")
if self.useSelection:
selection = self.inputLayer.selectedFeatures()
self.emit(SIGNAL("rangeCalculated( PyQt_PyObject )"), len(selection))
for f in selection:
featureId = f.id()
featGeometry = QgsGeometry(f.geometry())
pointsBefore += geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(self.tolerance)
pointsAfter += geomVertexCount(newGeometry)
self.inputLayer.changeGeometry(featureId, newGeometry)
self.emit(SIGNAL("featureProcessed()"))
self.mutex.lock()
s = self.stopMe
self.mutex.unlock()
if s == 1:
interrupted = True
break
else:
vProvider = self.inputLayer.dataProvider()
self.emit(SIGNAL("rangeCalculated( PyQt_PyObject )"), vProvider.featureCount())
f = QgsFeature()
fit = vProvider.getFeatures()
while fit.nextFeature(f):
featureId = f.id()
featGeometry = QgsGeometry(f.geometry())
pointsBefore += geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(self.tolerance)
pointsAfter += geomVertexCount(newGeometry)
self.inputLayer.changeGeometry(featureId, newGeometry)
self.emit(SIGNAL("featureProcessed()"))
self.mutex.lock()
s = self.stopMe
self.mutex.unlock()
if s == 1:
interrupted = True
break
# cleanup
if self.inputLayer.isEditable():
self.inputLayer.endEditCommand()
if shapeFileWriter is not None:
del shapeFileWriter
if not interrupted:
self.emit(SIGNAL("processingFinished( PyQt_PyObject )"), (pointsBefore, pointsAfter))
else:
self.emit(SIGNAL("processingInterrupted()"))
def runSimplify(self):
self.mutex.lock()
self.stopMe = 0
self.mutex.unlock()
interrupted = False
shapeFileWriter = None
pointsBefore = 0
pointsAfter = 0
if self.writeShape:
vProvider = self.inputLayer.dataProvider()
shapeFields = vProvider.fields()
crs = vProvider.crs()
wkbType = self.inputLayer.wkbType()
if not crs.isValid():
crs = None
shapeFileWriter = QgsVectorFileWriter(self.outputFileName,
self.outputEncoding,
shapeFields, wkbType, crs)
featureId = 0
if self.useSelection:
selection = self.inputLayer.selectedFeatures()
self.emit(SIGNAL("rangeCalculated( PyQt_PyObject )"),
len(selection))
for f in selection:
featGeometry = QgsGeometry(f.geometry())
attrMap = f.attributes()
pointsBefore += geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(self.tolerance)
pointsAfter += geomVertexCount(newGeometry)
feature = QgsFeature()
feature.setGeometry(newGeometry)
feature.setAttributes(attrMap)
shapeFileWriter.addFeature(feature)
featureId += 1
self.emit(SIGNAL("featureProcessed()"))
self.mutex.lock()
s = self.stopMe
self.mutex.unlock()
if s == 1:
interrupted = True
break
else:
self.emit(SIGNAL("rangeCalculated( PyQt_PyObject )"),
vProvider.featureCount())
f = QgsFeature()
fit = vProvider.getFeatures()
while fit.nextFeature(f):
featGeometry = QgsGeometry(f.geometry())
attrMap = f.attributes()
pointsBefore += geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(self.tolerance)
pointsAfter += geomVertexCount(newGeometry)
feature = QgsFeature()
feature.setGeometry(newGeometry)
feature.setAttributes(attrMap)
shapeFileWriter.addFeature(feature)
featureId += 1
self.emit(SIGNAL("featureProcessed()"))
self.mutex.lock()
s = self.stopMe
self.mutex.unlock()
if s == 1:
interrupted = True
break
else: # modify existing shapefile
if not self.inputLayer.isEditable():
self.inputLayer.startEditing()
self.inputLayer.beginEditCommand("Simplify line(s)")
if self.useSelection:
selection = self.inputLayer.selectedFeatures()
self.emit(SIGNAL("rangeCalculated( PyQt_PyObject )"),
len(selection))
for f in selection:
featureId = f.id()
featGeometry = QgsGeometry(f.geometry())
pointsBefore += geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(self.tolerance)
pointsAfter += geomVertexCount(newGeometry)
self.inputLayer.changeGeometry(featureId, newGeometry)
self.emit(SIGNAL("featureProcessed()"))
self.mutex.lock()
s = self.stopMe
self.mutex.unlock()
if s == 1:
interrupted = True
break
else:
vProvider = self.inputLayer.dataProvider()
self.emit(SIGNAL("rangeCalculated( PyQt_PyObject )"),
vProvider.featureCount())
f = QgsFeature()
fit = vProvider.getFeatures()
while fit.nextFeature(f):
featureId = f.id()
featGeometry = QgsGeometry(f.geometry())
pointsBefore += geomVertexCount(featGeometry)
newGeometry = featGeometry.simplify(self.tolerance)
pointsAfter += geomVertexCount(newGeometry)
self.inputLayer.changeGeometry(featureId, newGeometry)
self.emit(SIGNAL("featureProcessed()"))
self.mutex.lock()
s = self.stopMe
self.mutex.unlock()
if s == 1:
interrupted = True
break
# cleanup
if self.inputLayer.isEditable():
self.inputLayer.endEditCommand()
if shapeFileWriter is not None:
del shapeFileWriter
if not interrupted:
self.emit(SIGNAL("processingFinished( PyQt_PyObject )"),
(pointsBefore, pointsAfter))
else:
self.emit(SIGNAL("processingInterrupted()"))
