106 lines
4.3 KiB
Python

from sextante.core.GeoAlgorithm import GeoAlgorithm
import os.path
from PyQt4 import QtGui
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from sextante.parameters.ParameterVector import ParameterVector
from sextante.core.QGisLayers import QGisLayers
from sextante.ftools import ftools_utils
from sextante.parameters.ParameterTableField import ParameterTableField
from sextante.outputs.OutputVector import OutputVector
class MeanCoords(GeoAlgorithm):
POINTS = "POINTS"
WEIGHT = "WEIGHT"
OUTPUT = "OUTPUT"
UID = "UID"
WEIGHT = "WEIGHT"
def getIcon(self):
return QtGui.QIcon(os.path.dirname(__file__) + "/icons/mean.png")
def processAlgorithm(self, progress):
vlayer = QGisLayers.getObjectFromUri(self.getParameterValue(MeanCoords.POINTS))
weightField = self.getParameterValue(MeanCoords.WEIGHT)
uniqueField = self.getParameterValue(MeanCoords.UID)
provider = vlayer.dataProvider()
weightIndex = provider.fieldNameIndex(weightField)
uniqueIndex = provider.fieldNameIndex(uniqueField)
feat = QgsFeature()
allAttrs = provider.attributeIndexes()
provider.select(allAttrs)
sRs = provider.crs()
if uniqueIndex <> -1:
uniqueValues = ftools_utils.getUniqueValues(provider, int( uniqueIndex ) )
single = False
else:
uniqueValues = [QVariant(1)]
single = True
fieldList = { 0 : QgsField("MEAN_X", QVariant.Double), 1 : QgsField("MEAN_Y", QVariant.Double), 2 : QgsField("UID", QVariant.String) }
writer = self.getOutputFromName(MeanCoords.OUTPUT).getVectorWriter(fieldList, QGis.WKBPoint, sRs)
outfeat = QgsFeature()
points = []
weights = []
nFeat = provider.featureCount() * len(uniqueValues)
nElement = 0
for j in uniqueValues:
provider.rewind()
provider.select(allAttrs)
cx = 0.00
cy = 0.00
points = []
weights = []
while provider.nextFeature(feat):
nElement += 1
progress.setPercentage(nElement/nFeat * 100)
if single:
check = j.toString().trimmed()
else:
check = feat.attributeMap()[uniqueIndex].toString().trimmed()
if check == j.toString().trimmed():
cx = 0.00
cy = 0.00
if weightIndex == -1:
weight = 1.00
else:
try:
weight = float(feat.attributeMap()[weightIndex].toDouble()[0])
except:
weight = 1.00
geom = QgsGeometry(feat.geometry())
geom = ftools_utils.extractPoints(geom)
for i in geom:
cx += i.x()
cy += i.y()
points.append(QgsPoint((cx / len(geom)), (cy / len(geom))))
weights.append(weight)
sumWeight = sum(weights)
cx = 0.00
cy = 0.00
item = 0
for item, i in enumerate(points):
cx += i.x() * weights[item]
cy += i.y() * weights[item]
cx = cx / sumWeight
cy = cy / sumWeight
meanPoint = QgsPoint(cx, cy)
outfeat.setGeometry(QgsGeometry.fromPoint(meanPoint))
outfeat.addAttribute(0, QVariant(cx))
outfeat.addAttribute(1, QVariant(cy))
outfeat.addAttribute(2, QVariant(j))
writer.addFeature(outfeat)
if single:
break
del writer
def defineCharacteristics(self):
self.name = "Mean coordinate(s)"
self.group = "Analysis tools"
self.addParameter(ParameterVector(MeanCoords.POINTS, "Input layer", ParameterVector.VECTOR_TYPE_ANY))
self.addParameter(ParameterTableField(MeanCoords.WEIGHT, "Weight field", MeanCoords.POINTS))
self.addParameter(ParameterTableField(MeanCoords.UID, "Unique ID field", MeanCoords.POINTS))
self.addOutput(OutputVector(MeanCoords.OUTPUT, "Result"))