# -*- coding: utf-8 -*-
#-----------------------------------------------------------
#
# fTools
# Copyright (C) 2008-2011 Carson Farmer
# EMAIL: carson.farmer (at) gmail.com
# WEB : http://www.ftools.ca/fTools.html
#
# A collection of data management and analysis tools for vector data
#
#-----------------------------------------------------------
#
# licensed under the terms of GNU GPL 2
#
# 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.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
#---------------------------------------------------------------------
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from random import *
import math, ftools_utils
from ui_frmRandPoints import Ui_Dialog
class Dialog(QDialog, Ui_Dialog):
def __init__(self, iface):
QDialog.__init__(self, iface.mainWindow())
self.iface = iface
self.setupUi(self)
QObject.connect(self.toolOut, SIGNAL("clicked()"), self.outFile)
QObject.connect(self.inShape, SIGNAL("currentIndexChanged(QString)"), self.update)
self.progressBar.setValue(0)
self.setWindowTitle(self.tr("Random Points"))
self.buttonOk = self.buttonBox_2.button( QDialogButtonBox.Ok )
self.populateLayers()
def populateLayers( self ):
layers = ftools_utils.getLayerNames([QGis.Polygon, "Raster"])
self.inShape.blockSignals(True)
self.inShape.clear()
self.inShape.blockSignals(False)
self.inShape.addItems(layers)
# If input layer is changed, update field list
def update(self, inputLayer):
self.cmbField.clear()
changedLayer = ftools_utils.getMapLayerByName(unicode(inputLayer))
if changedLayer.type() == changedLayer.VectorLayer:
self.rdoStratified.setEnabled(True)
self.rdoDensity.setEnabled(True)
self.rdoField.setEnabled(True)
self.label_4.setEnabled(True)
changedLayer = ftools_utils.getVectorLayerByName(inputLayer)
changedFields = ftools_utils.getFieldList(changedLayer)
for f in changedFields:
if f.typeName().lower() == "integer":
self.cmbField.addItem(unicode(f.name()))
else:
self.rdoUnstratified.setChecked(True)
self.rdoStratified.setEnabled(False)
self.rdoDensity.setEnabled(False)
self.rdoField.setEnabled(False)
self.spnStratified.setEnabled(False)
self.spnDensity.setEnabled(False)
self.cmbField.setEnabled(False)
self.label_4.setEnabled(False)
# when 'OK' button is pressed, gather required inputs, and initiate random points generation
def accept(self):
self.buttonOk.setEnabled( False )
if self.inShape.currentText() == "":
QMessageBox.information(self, self.tr("Random Points"), self.tr("No input layer specified"))
elif self.outShape.text() == "":
QMessageBox.information(self, self.tr("Random Points"), self.tr("Please specify output shapefile"))
else:
inName = self.inShape.currentText()
self.progressBar.setValue(1)
outPath = self.outShape.text()
self.progressBar.setValue(2.5)
outName = ftools_utils.getShapefileName( outPath )
self.progressBar.setValue(5)
mLayer = ftools_utils.getMapLayerByName(unicode(inName))
if mLayer.type() == mLayer.VectorLayer:
inLayer = ftools_utils.getVectorLayerByName(unicode(inName))
if self.rdoUnstratified.isChecked():
design = self.tr("unstratified")
value = self.spnUnstratified.value()
elif self.rdoStratified.isChecked():
design = self.tr("stratified")
value = self.spnStratified.value()
elif self.rdoDensity.isChecked():
design = self.tr("density")
value = self.spnDensity.value()
else:
design = self.tr("field")
value = unicode(self.cmbField.currentText())
elif mLayer.type() == mLayer.RasterLayer:
inLayer = ftools_utils.getRasterLayerByName(unicode(inName))
design = self.tr("unstratified")
value = self.spnUnstratified.value()
else:
QMessageBox.information(self, self.tr("Random Points"), self.tr("Unknown layer type..."))
minimum = 0.00
self.progressBar.setValue(10)
if self.randomize(inLayer, outPath, minimum, design, value):
self.progressBar.setValue(100)
self.outShape.clear()
if self.addToCanvasCheck.isChecked():
addCanvasCheck = ftools_utils.addShapeToCanvas(unicode(outPath))
if not addCanvasCheck:
QMessageBox.warning( self, self.tr("Random Points"), self.tr( "Error loading output shapefile:\n%s" ) % ( unicode( outPath ) ))
self.populateLayers()
else:
QMessageBox.information(self, self.tr("Random Points"),self.tr("Created output shapefile:\n%s" ) % ( unicode( outPath )))
self.progressBar.setValue(0)
self.buttonOk.setEnabled( True )
def outFile(self):
self.outShape.clear()
( self.shapefileName, self.encoding ) = ftools_utils.saveDialog( self )
if self.shapefileName is None or self.encoding is None:
return
self.outShape.setText( self.shapefileName )
# combine all polygons in layer to create single polygon (slow for complex polygons)
def createSinglePolygon(self, vlayer):
provider = vlayer.dataProvider()
feat = QgsFeature()
geom = QgsGeometry()
fit = provider.getFeatures()
fit.nextFeature(feat)
geom = QgsGeometry(feat.geometry())
count = 10.00
add = ( 40.00 - 10.00 ) / provider.featureCount()
while fit.nextFeature(feat):
geom = geom.combine(QgsGeometry( feat.geometry() ))
count = count + add
self.progressBar.setValue(count)
return geom
# Generate list of random points
def simpleRandom(self, n, bound, xmin, xmax, ymin, ymax):
seed()
points = []
i = 1
count = 40.00
if n == 0:
return []
add = ( 70.00 - 40.00 ) / n
while i <= n:
pGeom = QgsGeometry().fromPoint(QgsPoint(xmin + (xmax-xmin) * random(), ymin + (ymax-ymin) * random()))
if pGeom.intersects(bound):
points.append(pGeom)
i = i + 1
count = count + add
self.progressBar.setValue(count)
return points
def vectorRandom(self, n, layer, xmin, xmax, ymin, ymax):
provider = layer.dataProvider()
index = ftools_utils.createIndex(provider)
seed()
points = []
feat = QgsFeature()
i = 1
count = 40.00
add = ( 70.00 - 40.00 ) / n
while i <= n:
point = QgsPoint(xmin + (xmax-xmin) * random(), ymin + (ymax-ymin) * random())
pGeom = QgsGeometry().fromPoint(point)
ids = index.intersects(pGeom.buffer(5,5).boundingBox())
for id in ids:
provider.getFeatures( QgsFeatureRequest().setFilterFid( int(id) ) ).nextFeature( feat )
tGeom = QgsGeometry(feat.geometry())
if pGeom.intersects(tGeom):
points.append(pGeom)
i = i + 1
count = count + add
self.progressBar.setValue(count)
break
return points
def randomize(self, inLayer, outPath, minimum, design, value):
outFeat = QgsFeature()
outFeat.initAttributes(1)
if design == self.tr("unstratified"):
ext = inLayer.extent()
if inLayer.type() == QgsMapLayer.RasterLayer:
points = self.simpleRandom(int(value), ext, ext.xMinimum(),
ext.xMaximum(), ext.yMinimum(), ext.yMaximum())
else:
points = self.vectorRandom(int(value), inLayer,
ext.xMinimum(), ext.xMaximum(), ext.yMinimum(), ext.yMaximum())
else:
points, featErrors = self.loopThruPolygons(inLayer, value, design)
if featErrors:
if len(featErrors) >= 10:
err_msg = "Too many features couldn't be calculated due to conversion error. "
err_msg += "Please check out message log for more info."
msgLogInstance = QgsMessageLog.instance( )
msgLogInstance.logMessage( "WARNING - fTools: " + self.tr( "Random Points" ) )
msgLogInstance.logMessage( "The following feature ids should be checked." )
for feat in featErrors:
msgLogInstance.logMessage( "Feature id: %d" % feat.id( ) )
msgLogInstance.logMessage( "End of features to be checked." )
else:
features_ids = []
for feat in featErrors:
features_ids.append( str( feat.id( ) ) )
erroneous_ids = ', '.join(features_ids)
err_msg = "The following features IDs couldn't be calculated due to conversion error: %s" % erroneous_ids
self.iface.messageBar().pushMessage("Errors", err_msg)
if len(points):
crs = self.iface.mapCanvas().mapRenderer().destinationCrs()
if not crs.isValid(): crs = None
fields = QgsFields()
fields.append( QgsField("ID", QVariant.Int) )
outFeat.setFields(fields)
check = QFile(self.shapefileName)
if check.exists():
if not QgsVectorFileWriter.deleteShapeFile(self.shapefileName):
return
writer = QgsVectorFileWriter(self.shapefileName, self.encoding, fields, QGis.WKBPoint, crs)
idVar = 0
count = 70.00
add = ( 100.00 - 70.00 ) / len(points)
for i in points:
outFeat.setGeometry(i)
outFeat.setAttribute(0, idVar)
writer.addFeature(outFeat)
idVar = idVar + 1
count = count + add
self.progressBar.setValue(count)
del writer
return True
return False
#
def loopThruPolygons(self, inLayer, numRand, design):
sProvider = inLayer.dataProvider()
sFeat = QgsFeature()
sGeom = QgsGeometry()
sPoints = []
if design == self.tr("field"):
index = sProvider.fieldNameIndex(numRand)
count = 10.00
add = 60.00 / sProvider.featureCount()
sFit = sProvider.getFeatures()
featureErrors = []
while sFit.nextFeature(sFeat):
sGeom = sFeat.geometry()
if design == self.tr("density"):
sDistArea = QgsDistanceArea()
value = int(round(numRand * sDistArea.measure(sGeom)))
elif design == self.tr("field"):
sAtMap = sFeat.attributes()
try:
value = int(sAtMap[index])
except (ValueError,TypeError):
featureErrors.append(sFeat)
continue
else:
value = numRand
sExt = sGeom.boundingBox()
sPoints.extend(self.simpleRandom(value, sGeom, sExt.xMinimum(), sExt.xMaximum(), sExt.yMinimum(), sExt.yMaximum()))
count = count + add
self.progressBar.setValue(count)
return sPoints, featureErrors