QGIS/python/plugins/processing/algs/qgis/PointsInPolygonWeighted.py

# -*- coding: utf-8 -*-

"""
***************************************************************************
    PointsInPolygon.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 QVariant
from qgis.core import QgsField, QgsFeatureRequest, QgsFeature, QgsGeometry
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterString
from processing.core.parameters import ParameterTableField
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector


class PointsInPolygonWeighted(GeoAlgorithm):

    POLYGONS = 'POLYGONS'
    POINTS = 'POINTS'
    OUTPUT = 'OUTPUT'
    FIELD = 'FIELD'
    WEIGHT = 'WEIGHT'

    # =========================================================================
    # def getIcon(self):
    #    return QIcon(os.path.dirname(__file__) + "/icons/sum_points.png")
    # =========================================================================

    def defineCharacteristics(self):
        self.name, self.i18n_name = self.trAlgorithm('Count points in polygon(weighted)')
        self.group, self.i18n_group = self.trAlgorithm('Vector analysis tools')

        self.addParameter(ParameterVector(self.POLYGONS,
                                          self.tr('Polygons'), [ParameterVector.VECTOR_TYPE_POLYGON]))
        self.addParameter(ParameterVector(self.POINTS,
                                          self.tr('Points'), [ParameterVector.VECTOR_TYPE_POINT]))
        self.addParameter(ParameterTableField(self.WEIGHT,
                                              self.tr('Weight field'), self.POINTS))
        self.addParameter(ParameterString(self.FIELD,
                                          self.tr('Count field name'), 'NUMPOINTS'))

        self.addOutput(OutputVector(self.OUTPUT, self.tr('Weighted count')))

    def processAlgorithm(self, progress):
        polyLayer = dataobjects.getObjectFromUri(self.getParameterValue(self.POLYGONS))
        pointLayer = dataobjects.getObjectFromUri(self.getParameterValue(self.POINTS))
        fieldName = self.getParameterValue(self.FIELD)
        fieldIdx = pointLayer.fieldNameIndex(self.getParameterValue(self.WEIGHT))

        polyProvider = polyLayer.dataProvider()
        fields = polyProvider.fields()
        fields.append(QgsField(fieldName, QVariant.Int))

        (idxCount, fieldList) = vector.findOrCreateField(polyLayer,
                                                         polyLayer.pendingFields(), fieldName)

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
            fields.toList(), polyProvider.geometryType(), polyProvider.crs())

        spatialIndex = vector.spatialindex(pointLayer)

        ftPoint = QgsFeature()
        outFeat = QgsFeature()
        geom = QgsGeometry()

        current = 0
        hasIntersections = False

        features = vector.features(polyLayer)
        total = 100.0 / float(len(features))
        for ftPoly in features:
            geom = ftPoly.geometry()
            attrs = ftPoly.attributes()

            count = 0
            hasIntersections = False
            points = spatialIndex.intersects(geom.boundingBox())
            if len(points) > 0:
                hasIntersections = True

            if hasIntersections:
                progress.setText(unicode(len(points)))
                for i in points:
                    request = QgsFeatureRequest().setFilterFid(i)
                    ftPoint = pointLayer.getFeatures(request).next()
                    tmpGeom = QgsGeometry(ftPoint.geometry())
                    if geom.contains(tmpGeom):
                        weight = unicode(ftPoint.attributes()[fieldIdx])
                        try:
                            count += float(weight)
                        except:
                            # Ignore fields with non-numeric values
                            pass

            outFeat.setGeometry(geom)
            if idxCount == len(attrs):
                attrs.append(count)
            else:
                attrs[idxCount] = count
            outFeat.setAttributes(attrs)
            writer.addFeature(outFeat)

            current += 1
            progress.setPercentage(int(current * total))

        del writer