mirror of
https://github.com/qgis/QGIS.git
synced 2025-02-27 00:33:48 -05:00
125 lines
4.9 KiB
Python
125 lines
4.9 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
RandomPointsLayer.py
|
|
---------------------
|
|
Date : April 2014
|
|
Copyright : (C) 2014 by Alexander Bruy
|
|
Email : alexander dot bruy 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__ = 'Alexander Bruy'
|
|
__date__ = 'April 2014'
|
|
__copyright__ = '(C) 2014, Alexander Bruy'
|
|
|
|
# This will get replaced with a git SHA1 when you do a git archive
|
|
|
|
__revision__ = '$Format:%H$'
|
|
|
|
import os
|
|
import random
|
|
|
|
from PyQt4.QtGui import QIcon
|
|
from PyQt4.QtCore import QVariant
|
|
from qgis.core import (QGis, QgsGeometry, QgsFields, QgsField, QgsSpatialIndex,
|
|
QgsPoint, QgsFeature, QgsFeatureRequest)
|
|
|
|
from processing.core.GeoAlgorithm import GeoAlgorithm
|
|
from processing.core.ProcessingLog import ProcessingLog
|
|
from processing.core.parameters import ParameterVector
|
|
from processing.core.parameters import ParameterNumber
|
|
from processing.core.outputs import OutputVector
|
|
from processing.tools import dataobjects, vector
|
|
|
|
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
|
|
|
|
|
|
class RandomPointsLayer(GeoAlgorithm):
|
|
|
|
VECTOR = 'VECTOR'
|
|
POINT_NUMBER = 'POINT_NUMBER'
|
|
MIN_DISTANCE = 'MIN_DISTANCE'
|
|
OUTPUT = 'OUTPUT'
|
|
|
|
def getIcon(self):
|
|
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'random_points.png'))
|
|
|
|
def defineCharacteristics(self):
|
|
self.name, self.i18n_name = self.trAlgorithm('Random points in layer bounds')
|
|
self.group, self.i18n_group = self.trAlgorithm('Vector creation tools')
|
|
self.addParameter(ParameterVector(self.VECTOR,
|
|
self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POLYGON]))
|
|
self.addParameter(ParameterNumber(self.POINT_NUMBER,
|
|
self.tr('Points number'), 1, None, 1))
|
|
self.addParameter(ParameterNumber(self.MIN_DISTANCE,
|
|
self.tr('Minimum distance'), 0.0, None, 0.0))
|
|
|
|
self.addOutput(OutputVector(self.OUTPUT, self.tr('Random points')))
|
|
|
|
def processAlgorithm(self, progress):
|
|
layer = dataobjects.getObjectFromUri(
|
|
self.getParameterValue(self.VECTOR))
|
|
pointCount = int(self.getParameterValue(self.POINT_NUMBER))
|
|
minDistance = float(self.getParameterValue(self.MIN_DISTANCE))
|
|
|
|
bbox = layer.extent()
|
|
idxLayer = vector.spatialindex(layer)
|
|
|
|
fields = QgsFields()
|
|
fields.append(QgsField('id', QVariant.Int, '', 10, 0))
|
|
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
|
|
fields, QGis.WKBPoint, layer.dataProvider().crs())
|
|
|
|
nPoints = 0
|
|
nIterations = 0
|
|
maxIterations = pointCount * 200
|
|
total = 100.0 / pointCount
|
|
|
|
index = QgsSpatialIndex()
|
|
points = dict()
|
|
|
|
request = QgsFeatureRequest()
|
|
|
|
random.seed()
|
|
|
|
while nIterations < maxIterations and nPoints < pointCount:
|
|
rx = bbox.xMinimum() + bbox.width() * random.random()
|
|
ry = bbox.yMinimum() + bbox.height() * random.random()
|
|
|
|
pnt = QgsPoint(rx, ry)
|
|
geom = QgsGeometry.fromPoint(pnt)
|
|
ids = idxLayer.intersects(geom.buffer(5, 5).boundingBox())
|
|
if len(ids) > 0 and \
|
|
vector.checkMinDistance(pnt, index, minDistance, points):
|
|
for i in ids:
|
|
f = layer.getFeatures(request.setFilterFid(i)).next()
|
|
tmpGeom = QgsGeometry(f.geometry())
|
|
if geom.within(tmpGeom):
|
|
f = QgsFeature(nPoints)
|
|
f.initAttributes(1)
|
|
f.setFields(fields)
|
|
f.setAttribute('id', nPoints)
|
|
f.setGeometry(geom)
|
|
writer.addFeature(f)
|
|
index.insertFeature(f)
|
|
points[nPoints] = pnt
|
|
nPoints += 1
|
|
progress.setPercentage(int(nPoints * total))
|
|
nIterations += 1
|
|
|
|
if nPoints < pointCount:
|
|
ProcessingLog.addToLog(ProcessingLog.LOG_INFO,
|
|
self.tr('Can not generate requested number of random points. '
|
|
'Maximum number of attempts exceeded.'))
|
|
|
|
del writer
|