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[processing] speedup Hub distance algorithm (fix #15012)

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This commit is contained in:
Alexander Bruy 2016-06-21 15:59:04 +03:00
parent 2d9b2a354b
commit e0c9733f64
1 changed files with 10 additions and 26 deletions
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36
python/plugins/processing/algs/qgis/HubDistance.py
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@ -26,7 +26,7 @@ __copyright__ = '(C) 2010, Michael Minn'
__revision__ = '$Format:%H$'
from qgis.PyQt.QtCore import QVariant
from qgis.core import QGis, QgsField, QgsGeometry, QgsDistanceArea, QgsFeature
from qgis.core import QGis, QgsField, QgsGeometry, QgsDistanceArea, QgsFeature, QgsFeatureRequest
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector
@ -106,12 +106,7 @@ class HubDistance(GeoAlgorithm):
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
fields, geomType, layerPoints.crs())
# Create array of hubs in memory
hubs = []
features = vector.features(layerHubs)
for f in features:
hubs.append(Hub(f.geometry().boundingBox().center(),
unicode(f[fieldName])))
index = vector.spatialindex(layerHubs)
distance = QgsDistanceArea()
distance.setSourceCrs(layerPoints.crs().srsid())
@ -123,17 +118,13 @@ class HubDistance(GeoAlgorithm):
for current, f in enumerate(features):
src = f.geometry().boundingBox().center()
closest = hubs[0]
hubDist = distance.measureLine(src, closest.point)
for hub in hubs:
dist = distance.measureLine(src, hub.point)
if dist < hubDist:
closest = hub
hubDist = dist
neighbors = index.nearestNeighbor(src, 1)
ft = layerHubs.getFeatures(QgsFeatureRequest().setFilterFid(neighbors[0])).next()
closest = ft.geometry().boundingBox().center()
hubDist = distance.measureLine(src, closest)
attributes = f.attributes()
attributes.append(closest.name)
attributes.append(ft[fieldName])
if units == 'Feet':
attributes.append(hubDist * 3.2808399)
elif units == 'Miles':
@ -142,8 +133,8 @@ class HubDistance(GeoAlgorithm):
attributes.append(hubDist / 1000.0)
elif units != 'Meters':
attributes.append(sqrt(
pow(src.x() - closest.point.x(), 2.0) +
pow(src.y() - closest.point.y(), 2.0)))
pow(src.x() - closest.x(), 2.0) +
pow(src.y() - closest.y(), 2.0)))
else:
attributes.append(hubDist)
@ -153,16 +144,9 @@ class HubDistance(GeoAlgorithm):
if geomType == QGis.WKBPoint:
feat.setGeometry(QgsGeometry.fromPoint(src))
else:
feat.setGeometry(QgsGeometry.fromPolyline([src, closest.point]))
feat.setGeometry(QgsGeometry.fromPolyline([src, closest]))
writer.addFeature(feat)
progress.setPercentage(int(current * total))
del writer
class Hub:
def __init__(self, point, name):
self.point = point
self.name = name