2013-06-09 16:05:09 +02:00

114 lines
4.4 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__ = '$Format:%H$'
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.algs.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 = "Vector 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)
weightIndex = layer.fieldNameIndex(weightField)
uniqueIndex = layer.fieldNameIndex(uniqueField)
fieldList = [QgsField("MEAN_X", QVariant.Double, "", 24, 15),
QgsField("MEAN_Y", QVariant.Double, "", 24, 15),
QgsField("UID", QVariant.String, "", 255)
]
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fieldList,
QGis.WKBPoint, layer.crs())
current = 0
features = QGisLayers.features(layer)
total = 100.0 / float(len(features))
means = {}
for feat in features:
current += 1
progress.setPercentage(current * total)
clazz = str(feat.attributes()[uniqueIndex]).strip()
if weightIndex == -1:
weight = 1.00
else:
try:
weight = float(feat.attributes()[weightIndex])
except:
weight = 1.00
if clazz not in means:
means[clazz] = (0,0,0)
cx,cy, totalweight = means[clazz]
geom = QgsGeometry(feat.geometry())
geom = utils.extractPoints(geom)
for i in geom:
cx += i.x() * weight
cy += i.y() * weight
totalweight += weight
means[clazz] = (cx, cy, totalweight)
for clazz, values in means.iteritems():
outFeat = QgsFeature()
cx = values[0] / values[2]
cy = values[1] / values[2]
meanPoint = QgsPoint(cx, cy)
outFeat.setGeometry(QgsGeometry.fromPoint(meanPoint))
outFeat.setAttributes([cx, cy, clazz])
writer.addFeature(outFeat)
del writer