def updateFieldList(self, layerName):
self.cmbGroupField.clear()
vLayer = utils.getVectorLayerByName(layerName)
fields = utils.getFieldList(vLayer)
for i in fields:
if fields[i].type() in [QVariant.Int, QVariant.String]:
self.cmbGroupField.addItem(fields[i].name())
def accept(self):
# check input parameters
if self.cmbRasterLayer.currentIndex() == -1:
QMessageBox.warning(self, self.tr("ZonalStats: Warning"), self.tr("Please select raster layer to analyse"))
return
if self.cmbVectorLayer.currentIndex() == -1:
QMessageBox.warning(self, self.tr("ZonalStats: Warning"), self.tr("Please select vector layer to analyse"))
return
if self.leReportFile.text().isEmpty():
QMessageBox.warning(
self, self.tr("ZonalStats: Warning"), self.tr("Please select where to save report file")
)
return
if self.leDataFile.text().isEmpty():
QMessageBox.warning(self, self.tr("ZonalStats: Warning"), self.tr("Please select where to save data file"))
return
rasterPath = utils.getRasterLayerByName(self.cmbRasterLayer.currentText()).source()
vLayer = utils.getVectorLayerByName(self.cmbVectorLayer.currentText())
reportPath = self.leReportFile.text()
dataPath = self.leDataFile.text()
self.progressBar.setRange(0, 3)
self.progressBar.setValue(0)
memLayer = utils.loadInMemory(vLayer)
memProvider = memLayer.dataProvider()
self.progressBar.setValue(self.progressBar.value() + 1)
# get pixel size (need it for area calculation)
pixelSize = utils.getRasterLayerByName(self.cmbRasterLayer.currentText()).rasterUnitsPerPixel()
# TODO: check attribute prefix
prefix = ""
# calculate zonal statistics
zs = QgsZonalStatistics(memLayer, rasterPath, prefix)
pd = QProgressDialog(self.tr("Calculating zonal statistics"), self.tr("Abort..."), 0, 0)
zs.calculateStatistics(pd)
self.progressBar.setValue(self.progressBar.value() + 1)
if pd.wasCanceled():
QMessageBox.error(
self,
self.tr("ZonalStats: Error"),
self.tr("Hey!.. You abort statistics calculation, so there are no data for analysis. Exiting..."),
)
self.progressBar.setValue(0)
return
# save full statistics to file near the input shapefile
# fi = QFileInfo( vLayer.source() )
# fPath = fi.path() + "/" + fi.completeBaseName() + "_full_stat.csv"
# utils.saveStatsToCSV( memLayer, fPath )
# get count field index
# idxCount = memLayer.fieldNameIndex( "count" )
idxCount = memLayer.fieldNameIndex("sum")
reportData = []
ft = QgsFeature()
# generate report
if self.chkGroupZones.isChecked():
grpFieldIndex = 0
isString = False
fieldName = self.cmbGroupField.currentText()
for k, v in memProvider.fields().iteritems():
if v.name() == fieldName:
if v.type() == QVariant.String:
isString = True
grpFieldIndex = k
break
# get unique values
uniqueValues = memProvider.uniqueValues(grpFieldIndex)
allAttrs = memProvider.attributeIndexes()
sqlString = None
if isString:
sqlString = QString(fieldName + " = '%1'")
else:
sqlString = QString(fieldName + " = %1")
# create zones
for v in uniqueValues:
groupName = v.toString()
qry = sqlString.arg(groupName)
fIds = utils.searchInLayer(memLayer, qry)
stats = [unicode(groupName), str(len(fIds)), 0]
for i in fIds:
memLayer.featureAtId(i, ft, False, True)
attrMap = ft.attributeMap()
stats[2] += attrMap[idxCount].toFloat()[0]
stats[2] = str(stats[2] * pixelSize)
reportData.append(stats)
else:
allAttrs = memProvider.attributeIndexes()
memLayer.select(allAttrs, QgsRectangle(), False)
nameFieldIndex = memLayer.fieldNameIndex(self.cmbGroupField.currentText())
while memLayer.nextFeature(ft):
attrMap = ft.attributeMap()
stats = [unicode(attrMap[nameFieldIndex].toString()), "1", "0"]
stats[2] = str(attrMap[idxCount].toFloat()[0] * pixelSize)
reportData.append(stats)
# save report as HTML
rpt = utils.writeReport(reportPath, dataPath, reportData, unicode(self.cmbGroupField.currentText()))
self.progressBar.setValue(self.progressBar.value() + 1)
# display report in viewer
self.teReport.setHtml(rpt)
self.progressBar.setValue(0)
memLayer = None
