2012-10-11 20:27:47 +03:00

154 lines
5.3 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
MeanCoords.py
---------------------
Date : August 2012
Copyright : (C) 2012 by Victor Olaya
Email : volayaf at gmail dot com
***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************
"""
__author__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import os.path
from PyQt4 import QtGui
from PyQt4.QtCore import *
from qgis.core import *
from sextante.core.GeoAlgorithm import GeoAlgorithm
from sextante.core.QGisLayers import QGisLayers
from sextante.parameters.ParameterTableField import ParameterTableField
from sextante.parameters.ParameterVector import ParameterVector
from sextante.outputs.OutputVector import OutputVector
from sextante.ftools import FToolsUtils as utils
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 defineCharacteristics(self):
self.name = "Mean coordinate(s)"
self.group = "Analysis tools"
self.addParameter(ParameterVector(self.POINTS, "Input layer", ParameterVector.VECTOR_TYPE_ANY))
self.addParameter(ParameterTableField(self.WEIGHT, "Weight field", MeanCoords.POINTS, ParameterTableField.DATA_TYPE_NUMBER))
self.addParameter(ParameterTableField(self.UID, "Unique ID field", MeanCoords.POINTS, ParameterTableField.DATA_TYPE_NUMBER))
self.addOutput(OutputVector(MeanCoords.OUTPUT, "Result"))
def processAlgorithm(self, progress):
layer = QGisLayers.getObjectFromUri(self.getParameterValue(self.POINTS))
weightField = self.getParameterValue(self.WEIGHT)
uniqueField = self.getParameterValue(self.UID)
output = self.getOutputValue(self.OUTPUT)
provider = layer.dataProvider()
weightIndex = layer.fieldNameIndex(weightField)
uniqueIndex = layer.fieldNameIndex(uniqueField)
if uniqueIndex <> -1:
uniqueValues = layer.uniqueValues(uniqueIndex)
single = False
else:
uniqueValues = [QVariant(1)]
single = True
fieldList = {0 : QgsField("MEAN_X", QVariant.Double, "", 24, 15),
1 : QgsField("MEAN_Y", QVariant.Double, "", 24, 15),
2 : QgsField("UID", QVariant.String, "", 255)
}
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fieldList,
QGis.WKBPoint, provider.crs())
current = 0
total = 100.0 / float(provider.featureCount() * len(uniqueValues))
feat = QgsFeature()
outFeat = QgsFeature()
for j in uniqueValues:
provider.rewind()
layer.select([weightIndex, uniqueIndex])
cx = 0.00
cy = 0.00
points = []
weights = []
while layer.nextFeature(feat):
current += 1
progress.setPercentage(current * total)
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 = 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