QGIS/python/plugins/sextante/algs/ftools/PointsInPolygon.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 *

from qgis.core import *

from sextante.core.GeoAlgorithm import GeoAlgorithm
from sextante.core.QGisLayers import QGisLayers
from sextante.core.SextanteLog import SextanteLog
from sextante.parameters.ParameterVector import ParameterVector
from sextante.parameters.ParameterString import ParameterString
from sextante.outputs.OutputVector import OutputVector
from sextante.algs.ftools import FToolsUtils as utils


class PointsInPolygon(GeoAlgorithm):

    POLYGONS = "POLYGONS"
    POINTS = "POINTS"
    OUTPUT = "OUTPUT"
    FIELD = "FIELD"

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

    def defineCharacteristics(self):
        self.name = "Count points in polygon"
        self.group = "Vector analysis tools"
        self.addParameter(ParameterVector(self.POLYGONS, "Polygons", ParameterVector.VECTOR_TYPE_POLYGON))
        self.addParameter(ParameterVector(self.POINTS, "Points", ParameterVector.VECTOR_TYPE_POINT))
        self.addParameter(ParameterString(self.FIELD, "Count field name", "NUMPOINTS"))

        self.addOutput(OutputVector(self.OUTPUT, "Result"))

    def processAlgorithm(self, progress):
        polyLayer = QGisLayers.getObjectFromUri(self.getParameterValue(self.POLYGONS))
        pointLayer = QGisLayers.getObjectFromUri(self.getParameterValue(self.POINTS))
        fieldName = self.getParameterValue(self.FIELD)

        polyProvider = polyLayer.dataProvider()
        pointProvider = pointLayer.dataProvider()
        if polyProvider.crs() != pointProvider.crs():
            SextanteLog.addToLog(SextanteLog.LOG_WARNING,
                                 "CRS warning: Input layers have non-matching CRS. This may cause unexpected results.")

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

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

        spatialIndex = utils.createSpatialIndex(pointLayer)

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

        current = 0
        hasIntersections = False

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

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

            if hasIntersections:
                for i in points:
                    pointLayer.featureAtId(int(i), ftPoint, True, False)
                    tmpGeom = QgsGeometry(ftPoint.geometry())
                    if geom.contains(tmpGeom):
                        count += 1

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

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

        del writer