def createMemLayer(line, breaksList):
'''
create memory layer storing all reaches
:return:
'''
# create layer
vl = QgsVectorLayer("LineString", "sinuosity_river", "memory")
pr = vl.dataProvider()
# add fields
pr.addAttributes([
QgsField("reach", QVariant.Int),
QgsField("sinuosity", QVariant.Double),
QgsField("Length", QVariant.Double)
])
vl.updateFields()
# create breaks with initial and final
bk = sorted(breaksList)
bk.insert(0, 0)
bk.append(line.length())
for breack in range(1, len(bk)):
ptInt = line.interpolate(bk[breack - 1])
ptFin = line.interpolate(bk[breack])
reach = splitLine(line, ptInt, ptFin)
# sinuosity calc
dist = qgisdist(ptInt, ptFin)
lenReach = bk[breack] - bk[breack - 1]
# add a feature
fet = QgsFeature()
fet.setGeometry(QgsGeometry.fromPolylineXY(reach))
fet.setAttributes([breack, lenReach / dist, str(lenReach)])
pr.addFeatures([fet])
#vl.updateExtents()
vl.commitChanges()
return vl
def run(self):
QgsMessageLog.logMessage(f'Started task {self.description()}',
'TracingCAJ', Qgis.Info)
epsg = self.__hidrometers.crs().postgisSrid()
uri = "LineString?crs=epsg:" + str(
epsg
) + "&field=id:integer" "&field=distance:double(20,2)&index=yes"
dist = QgsVectorLayer(uri, 'dist', 'memory')
QgsProject.instance().addMapLayer(dist)
prov = dist.dataProvider()
points_features = [
point_feature
for point_feature in self.__hidrometers.getFeatures()
]
feats = []
if len(points_features) > 0:
for p in points_features:
nearest_pipe = self.find_nearest_pipelines(p.geometry())
try:
minDistPoint = nearest_pipe.closestSegmentWithContext(
p.geometry().asPoint())[1]
feat = QgsFeature()
feat.setGeometry(
QgsGeometry.fromPolylineXY(
[p.geometry().asPoint(), minDistPoint]))
feat.setAttributes(
[points_features.index(p),
feat.geometry().length()])
feats.append(feat)
except Exception as e:
print(p.id())
prov.addFeatures(feats)
