Python QgsPoint.sqrDist方法代码示例

# 需要导入模块: from qgis.core import QgsPoint [as 别名]
# 或者: from qgis.core.QgsPoint import sqrDist [as 别名]
    def snapGeometry(self, geometry, snapTolerance, mode=PreferNodes):
        """
        Snaps a QgsGeometry in the reference layer
        :param geometry: QgsGeometry
        :param snapTolerance: float
        :param mode: DsgGeometrySnapper.PreferNodes or DsgGeometrySnapper.PreferClosest
        :return:
        """
        center = QgsPointV2(geometry.boundingBox().center())

        # Get potential reference features and construct snap index
        refGeometries = []
        searchBounds = geometry.boundingBox()
        searchBounds.grow(snapTolerance)
        # filter by bounding box to get candidates
        refFeatureIds = self.index.intersects(searchBounds)

        # End here in case we don't find candidates
        if len(refFeatureIds) == 0:
            return geometry

        # speeding up the process to consider only intersecting geometries
        refFeatureRequest = QgsFeatureRequest().setFilterFids(refFeatureIds)
        for refFeature in self.referenceLayer.getFeatures(refFeatureRequest):
            refGeometry = refFeature.geometry()
            segments = self.breakQgsGeometryIntoSegments(refGeometry)
            # testing intersection
            for segment in segments:
                if segment.intersects(searchBounds):
                    refGeometries.append(segment)

        # End here in case we don't find geometries
        if len(refGeometries) == 0:
            return geometry

        # building geometry index
        refDict, index = self.buildReferenceIndex(refGeometries)
        refSnapIndex = DsgSnapIndex(center, 10*snapTolerance)
        for geom in refGeometries:
            refSnapIndex.addGeometry(geom.geometry())

        # Snap geometries
        subjGeom = geometry.geometry().clone()
        subjPointFlags = []

        # Pass 1: snap vertices of subject geometry to reference vertices
        for iPart in xrange(subjGeom.partCount()):
            subjPointFlags.append([])
            for iRing in xrange(subjGeom.ringCount(iPart)):
                subjPointFlags[iPart].append([])
                for iVert in xrange(self.polyLineSize(subjGeom, iPart, iRing)):
                    vidx = QgsVertexId(iPart, iRing, iVert, QgsVertexId.SegmentVertex)
                    p = QgsPointV2(subjGeom.vertexAt(vidx))
                    pF = QgsPoint(p.toQPointF())
                    snapPoint, snapSegment = refSnapIndex.getSnapItem(p, snapTolerance)
                    success = snapPoint or snapSegment
                    if not success:
                        subjPointFlags[iPart][iRing].append(DsgGeometrySnapper.Unsnapped )
                    else:
                        if mode == DsgGeometrySnapper.PreferNodes:
                            # Prefer snapping to point
                            if snapPoint:
                                subjGeom.moveVertex(vidx, snapPoint.getSnapPoint(p))
                                subjPointFlags[iPart][iRing].append(DsgGeometrySnapper.SnappedToRefNode)
                            elif snapSegment:
                                subjGeom.moveVertex( vidx, snapSegment.getSnapPoint(p))
                                subjPointFlags[iPart][iRing].append(DsgGeometrySnapper.SnappedToRefSegment)
                        elif mode == DsgGeometrySnapper.PreferClosest:
                            nodeSnap = None
                            segmentSnap = None
                            distanceNode = sys.float_info.max
                            distanceSegment = sys.float_info.max
                            if snapPoint:
                                nodeSnap = snapPoint.getSnapPoint(p)
                                nodeSnapF = QgsPoint(nodeSnap.toQPointF())
                                distanceNode = nodeSnapF.sqrDist(pF)
                            if snapSegment:
                                segmentSnap = snapSegment.getSnapPoint(p)
                                segmentSnapF = QgsPoint(segmentSnap.toQPointF())
                                distanceSegment = segmentSnapF.sqrDist(pF)
                            if snapPoint and (distanceNode < distanceSegment):
                                subjGeom.moveVertex( vidx, nodeSnap )
                                subjPointFlags[iPart][iRing].append(DsgGeometrySnapper.SnappedToRefNode)
                            elif snapSegment:
                                subjGeom.moveVertex(vidx, segmentSnap)
                                subjPointFlags[iPart][iRing].append(DsgGeometrySnapper.SnappedToRefSegment)

        #nothing more to do for points
        if isinstance(subjGeom, QgsPointV2):
            return QgsGeometry(subjGeom)
        
        # SnapIndex for subject feature
        subjSnapIndex = DsgSnapIndex(center, 10*snapTolerance)
        subjSnapIndex.addGeometry(subjGeom)
        
        origSubjGeom = subjGeom.clone()
        origSubjSnapIndex = DsgSnapIndex(center, 10*snapTolerance)
        origSubjSnapIndex.addGeometry(origSubjGeom)
        
        # Pass 2: add missing vertices to subject geometry
#.........这里部分代码省略.........

# 需要导入模块: from qgis.core import QgsPoint [as 别名]
# 或者: from qgis.core.QgsPoint import sqrDist [as 别名]

#.........这里部分代码省略.........
				##  BEGIN DISTANCE CODE!
				distance_dictionary = {}
				DList_TH_stops = defaultdict(list)
				### (temporarily) set ref to TAT in case
				##Enter data into Dictionary
				iter = vltWM.getFeatures()
				#iter = TAToutput.getFeatures()
				##THstopList = []
				for feature in iter:
					##identifies attributes for future use
					#print "Feature ID %d: " % feature.id()
					trailhead_id = feature[str('FEAT_ID')]
					#print trailhead_id
					geom = feature.geometry()
					th_x = geom.asPoint().x()	
					th_y = geom.asPoint().y()
					th_point = QgsPoint(th_x,th_y)
					#transit_stop_id = feature['stop_id']
					iter_stops = TAT_layer.getFeatures() ###[new layer here?]
					for stop_feature in iter_stops:
						stop_id = stop_feature[str('stop_id')]
						th_id = stop_feature[str('FEAT_ID')]
						if th_id == trailhead_id:
							stop_geom = stop_feature.geometry()
							stop_id = stop_feature['stop_id']
							DList_TH_stops[th_id].append(stop_id)
							stop_x = stop_geom.asPoint().x()	
							stop_y = stop_geom.asPoint().y()
							s_point = QgsPoint(stop_x,stop_y)
							stop_distance = 0
							a = numpy.array(th_point)
							b = numpy.array(s_point)
							##stop_distance = numpy.sqrt(numpy.sum(a-b)**2)
							stop_distance =  math.sqrt(th_point.sqrDist(s_point))
							#print th_id
							#print stop_id
							#print stop_distance
							####print math.sqrt(th_point.sqrDist(s_point))
							th_stop = str(trailhead_id) + ":" + str(stop_id)
							distance_dictionary[th_stop] = stop_distance
							#if stop_distance < BufferDistance:
							#    distance_dictionary[th_stop] = stop_distance 		
				##outputGeoJSON
				vl_outTH = QgsVectorLayer("Point?crs=EPSG:4326", "stop_points", "memory")
				pr_outTH = vl_outTH.dataProvider()
				#
				# changes are only possible when editing the layer
				vl_outTH.startEditing()
				# add fields
				##pr_outTH.addAttributes([QgsField(th_id_field, QVariant.Int),QgsField(th_name_field, QVariant.String),QgsField("number_stops_nearby", QVariant.Int),QgsField("stops_near", QVariant.String),QgsField("stops_near_dist", QVariant.String)])
				pr_outTH.addAttributes([QgsField(th_id_field, QVariant.Int),QgsField(th_name_field, QVariant.String),QgsField("number_stops_nearby", QVariant.Int),QgsField("stops_near", QVariant.String),QgsField("stops_distances", QVariant.String)])
				index = 0
				iter = trailhead_layer.getFeatures()
				for feature in iter:
					geom = feature.geometry()
					feature_id = feature[th_id_field]
					feature_name = feature[th_name_field]
					#stops_near = str(DList_TH_stops[feature_id])
					num_stops_near = 0
					stops_near_in = DList_TH_stops[feature_id]
					stops_near = []
					for t in stops_near_in:
						#print t
						if not t in stops_near:
							stops_near.append(t)					
					stops_near.sort()