def __init__(self, iface):
QtGui.QDialog.__init__(self)
self.iface = iface
# Set up the user interface from Designer.
self.ui = Ui_DissolveWithStats()
self.ui.setupUi(self)
# connect changed index signal in comboLayerList
self.ui.comboLayerList.currentIndexChanged[int].connect(self.onChangedValueLayer)
# connect changed index signal in comboFieldList
self.ui.comboFieldList.currentIndexChanged[int].connect(self.onChangedValueField)
# connect click on browse button, to display file dialog for output shapefile
self.ui.outButton.clicked.connect(self.outFile)
# connect OK button to validation function
self.ui.buttonBox.accepted.connect(self.validation)
# connect Cancel button to reject function
self.ui.buttonBox.rejected.connect(self.reject)
# to get all the vector layers names to populate combo box comboLayerList
legendInterface = self.iface.legendInterface()
listLayerName = [i.name() for i in legendInterface.layers() if i.type() == QgsMapLayer.VectorLayer]
# add all these layer names to combo box comboLayerList
self.ui.comboLayerList.addItems(listLayerName)
# populate the field table header
listHeaders = ["name", "type", "keep", "stat"]
self.ui.tableFields.setHorizontalHeaderLabels(listHeaders)
# set column widths for field table
self.ui.tableFields.setColumnWidth(0,120)
self.ui.tableFields.setColumnWidth(1,80)
self.ui.tableFields.setColumnWidth(2,80)
self.ui.tableFields.setColumnWidth(3,100)
# Run the dialog event loop
result = self.exec_()
# if Cancel was pressed
if result == QtGui.QFileDialog.Rejected:
return
# If OK was pressed
if result == QtGui.QFileDialog.Accepted:
# try:
# get selected layer in combo box comboLayerList
selectedLayerName = self.ui.comboLayerList.currentText()
# get selected field in combo box comboFieldList
selectedFieldName = self.ui.comboFieldList.currentText()
# get fields to keep and stats to calculate
listKeep = []
listStats = []
for row in range(self.ui.tableFields.rowCount()):
listKeep.append(self.ui.tableFields.cellWidget(row, 2).checkState())
listStats.append(self.ui.tableFields.cellWidget(row,3).currentText())
# get output shape
output = self.ui.outShape.text()
# run qgis:dissolve algorithm from processing module
processing.runalg("qgis:dissolve", selectedLayerName, "false", selectedFieldName, output)
# calculate new field values
listRes = self.calculateFields(listKeep, listStats, output)
# integrates these new values in the output attribute table, and remove fields if necessary
self.setAttributes(listRes, listKeep, output)
# add layer to map if checkBoxAddFile is checked
if self.ui.checkBoxAddFile.checkState() == 2:
self.addFile(output)
def __init__(self, iface):
QtGui.QDialog.__init__(self)
self.iface = iface
# Set up the user interface from Designer.
self.ui = Ui_DissolveWithStats()
self.ui.setupUi(self)
# connect changed index signal in comboLayerList
self.ui.comboLayerList.currentIndexChanged[int].connect(
self.onChangedValueLayer)
# connect changed index signal in comboFieldList
self.ui.comboFieldList.currentIndexChanged[int].connect(
self.onChangedValueField)
# connect click on browse button, to display file dialog for output shapefile
self.ui.outButton.clicked.connect(self.outFile)
# connect OK button to validation function
self.ui.buttonBox.accepted.connect(self.validation)
# connect Cancel button to reject function
self.ui.buttonBox.rejected.connect(self.reject)
# to get all the vector layers names to populate combo box comboLayerList
legendInterface = self.iface.legendInterface()
listLayerName = [
i.name() for i in legendInterface.layers()
if i.type() == QgsMapLayer.VectorLayer
]
# add all these layer names to combo box comboLayerList
self.ui.comboLayerList.addItems(listLayerName)
# populate the field table header
listHeaders = ["name", "type", "keep", "stat"]
self.ui.tableFields.setHorizontalHeaderLabels(listHeaders)
# set column widths for field table
self.ui.tableFields.setColumnWidth(0, 120)
self.ui.tableFields.setColumnWidth(1, 80)
self.ui.tableFields.setColumnWidth(2, 80)
self.ui.tableFields.setColumnWidth(3, 100)
# Run the dialog event loop
result = self.exec_()
# if Cancel was pressed
if result == QtGui.QFileDialog.Rejected:
return
# If OK was pressed
if result == QtGui.QFileDialog.Accepted:
# try:
# get selected layer in combo box comboLayerList
selectedLayerName = self.ui.comboLayerList.currentText()
# get selected field in combo box comboFieldList
selectedFieldName = self.ui.comboFieldList.currentText()
# get fields to keep and stats to calculate
listKeep = []
listStats = []
for row in range(self.ui.tableFields.rowCount()):
listKeep.append(
self.ui.tableFields.cellWidget(row, 2).checkState())
listStats.append(
self.ui.tableFields.cellWidget(row, 3).currentText())
# get output shape
output = self.ui.outShape.text()
# run qgis:dissolve algorithm from processing module
processing.runalg("qgis:dissolve", selectedLayerName, "false",
selectedFieldName, output)
# calculate new field values
listRes = self.calculateFields(listKeep, listStats, output)
# integrates these new values in the output attribute table, and remove fields if necessary
self.setAttributes(listRes, listKeep, output)
# add layer to map if checkBoxAddFile is checked
if self.ui.checkBoxAddFile.checkState() == 2:
self.addFile(output)
class DissolveWithStatsDialog(QtGui.QDialog, Ui_DissolveWithStats):
def __init__(self, iface):
QtGui.QDialog.__init__(self)
self.iface = iface
# Set up the user interface from Designer.
self.ui = Ui_DissolveWithStats()
self.ui.setupUi(self)
# connect changed index signal in comboLayerList
self.ui.comboLayerList.currentIndexChanged[int].connect(self.onChangedValueLayer)
# connect changed index signal in comboFieldList
self.ui.comboFieldList.currentIndexChanged[int].connect(self.onChangedValueField)
# connect click on browse button, to display file dialog for output shapefile
self.ui.outButton.clicked.connect(self.outFile)
# connect OK button to validation function
self.ui.buttonBox.accepted.connect(self.validation)
# connect Cancel button to reject function
self.ui.buttonBox.rejected.connect(self.reject)
# to get all the vector layers names to populate combo box comboLayerList
legendInterface = self.iface.legendInterface()
listLayerName = [i.name() for i in legendInterface.layers() if i.type() == QgsMapLayer.VectorLayer]
# add all these layer names to combo box comboLayerList
self.ui.comboLayerList.addItems(listLayerName)
# populate the field table header
listHeaders = ["name", "type", "keep", "stat"]
self.ui.tableFields.setHorizontalHeaderLabels(listHeaders)
# set column widths for field table
self.ui.tableFields.setColumnWidth(0,120)
self.ui.tableFields.setColumnWidth(1,80)
self.ui.tableFields.setColumnWidth(2,80)
self.ui.tableFields.setColumnWidth(3,100)
# Run the dialog event loop
result = self.exec_()
# if Cancel was pressed
if result == QtGui.QFileDialog.Rejected:
return
# If OK was pressed
if result == QtGui.QFileDialog.Accepted:
# try:
# get selected layer in combo box comboLayerList
selectedLayerName = self.ui.comboLayerList.currentText()
# get selected field in combo box comboFieldList
selectedFieldName = self.ui.comboFieldList.currentText()
# get fields to keep and stats to calculate
listKeep = []
listStats = []
for row in range(self.ui.tableFields.rowCount()):
listKeep.append(self.ui.tableFields.cellWidget(row, 2).checkState())
listStats.append(self.ui.tableFields.cellWidget(row,3).currentText())
# get output shape
output = self.ui.outShape.text()
# run qgis:dissolve algorithm from processing module
processing.runalg("qgis:dissolve", selectedLayerName, "false", selectedFieldName, output)
# calculate new field values
listRes = self.calculateFields(listKeep, listStats, output)
# integrates these new values in the output attribute table, and remove fields if necessary
self.setAttributes(listRes, listKeep, output)
# add layer to map if checkBoxAddFile is checked
if self.ui.checkBoxAddFile.checkState() == 2:
self.addFile(output)
# except:
# QtGui.QMessageBox.warning(self, 'Oops', 'Sorry, something went wrong', QtGui.QMessageBox.Ok)
# check if all the dialog parameters are valid
def validation(self):
message = ''
# get list of kept fields
if self.ui.comboLayerList.currentText() != '':
listKeep = []
for row in range(self.ui.tableFields.rowCount()):
listKeep.append(self.ui.tableFields.cellWidget(row, 2).checkState())
# get selected layer, to test self.ui.outShape.text()
if self.ui.comboLayerList.currentText() != '':
index = self.ui.comboLayerList.currentIndex()
legendInterface = self.iface.legendInterface()
listLayers = [layer for layer in legendInterface.layers() if layer.type() == QgsMapLayer.VectorLayer]
selectedLayer = listLayers[index]
outfile = QgsVectorFileWriter(self.ui.outShape.text(), "utf-8", selectedLayer.dataProvider().fields(), selectedLayer.dataProvider().geometryType(), selectedLayer.crs())
# if no layer is selected :
if self.ui.comboLayerList.currentText() == '':
message = 'No layer selected\nQGIS must have at least one vector layer loaded'
# if a layer is selected but doesn't have any field
elif self.ui.comboFieldList.currentText() == '':
message = 'No Field selected\nThe selected layer must have at least one field'
# if layer and dissolve field ok, but no fields are checked to be kept
elif 2 not in listKeep:
message = 'Please select at least one field to be kept'
# if no output is selected:
elif self.ui.outShape.text() == '':
message = 'No output layer\nPlease click on Browse button to specify output layer'
# if error in output shapefile path (permission problem for example)
elif (outfile.hasError() != QgsVectorFileWriter.NoError):
message = "Sorry, could not create output shapefile"
# if output does not end in .shp (can happen if user wrote it directly in the QLineEdit box)
elif self.ui.outShape.text()[-4:] not in ['.shp', '.SHP']:
self.ui.outShape.setText(self.ui.outShape.text() + '.shp')
# if something is wrong : show warning message
if message != '':
QtGui.QMessageBox.warning(self, 'Information missing or invalid', message, QtGui.QMessageBox.Ok)
# if everything is ok : proceed
else:
self.accept()
# if selected value in comboLayerList changes :
# actualize the values in comboFieldList and in tableFields
def onChangedValueLayer(self, index):
# get list of all vector layers in QGIS
legendInterface = self.iface.legendInterface()
listLayers = [layer for layer in legendInterface.layers() if layer.type() == QgsMapLayer.VectorLayer]
# get name of selected layer
provider = listLayers[index].dataProvider()
fields = provider.fields()
listFieldNames = [field.name() for field in fields]
# clear the combo box comboFieldList
self.ui.comboFieldList.clear()
# add all these field names to combo box comboFieldList
self.ui.comboFieldList.addItems(listFieldNames)
# add as many rows in the field table as fields in the shape, minus one
self.ui.tableFields.setRowCount(len(fields))
# populate columns in field table
for i in range (self.ui.tableFields.rowCount()):
# first column : field names
nameitem = QtGui.QTableWidgetItem(fields[i].name())
# the names are not editable
nameitem.setFlags(QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEnabled)
self.ui.tableFields.setItem(i, 0, nameitem)
# second column : field types
typeitem = QtGui.QTableWidgetItem(fields[i].typeName())
# the types are not editable
typeitem.setFlags(QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEnabled)
self.ui.tableFields.setItem(i, 1, typeitem)
# third column : check box
keepcheckbox = QtGui.QCheckBox()
keepcheckbox.setCheckState(QtCore.Qt.Checked)
keepitem = self.ui.tableFields.setCellWidget(i, 2, keepcheckbox)
# fourth column : stat
listStat = QtGui.QComboBox()
# if field is numeric
if fields[i].type() in [QtCore.QVariant.Int, QtCore.QVariant.Double]:
listStat.addItems(statNum)
# if field is not numeric
else:
listStat.addItems(statElse)
statitem = self.ui.tableFields.setCellWidget(i, 3, listStat)
# enable all field lists
self.ui.tableFields.cellWidget(i, 3).setEnabled(True)
# disable list for first field (since it is selected by default when a new layer is selected)
self.ui.tableFields.cellWidget(0, 3).setEnabled(False)
# if selected value in comboFieldList changes :
# re-enable the stats list for ex-selected value, disable it for selected value
def onChangedValueField(self, index):
if self.ui.tableFields.cellWidget(index, 3):
# enable all field lists
for i in range (self.ui.tableFields.rowCount()):
self.ui.tableFields.cellWidget(i, 3).setEnabled(True)
# disable current field list
self.ui.tableFields.cellWidget(index, 3).setEnabled(False)
# creation of the output shapefile
def outFile(self): # by Carson Farmer 2008
# display file dialog for output shapefile
self.ui.outShape.clear()
fileDialog = QtGui.QFileDialog()
fileDialog.setConfirmOverwrite(False)
outName = fileDialog.getSaveFileName(self, "Output Shapefile",".", "Shapefiles (*.shp)")
outPath = QtCore.QFileInfo(outName).absoluteFilePath()
if not outPath.upper().endswith(".SHP"):
outPath = outPath + ".shp"
if outName:
self.ui.outShape.clear()
self.ui.outShape.insert(outPath)
# gets the median from a list of numbers
def median(self, l):
# sorts list, get list length
l.sort()
z = len(l)
# if the list has an uneven number of elements
if z%2:
return l[z/2]
# if the list has an even number of elements
else:
return (l[(z/2)-1] + l[z/2]) / 2.0
# gets standard deviation from a list of numbers
def standard_dev(self, l):
mean = sum(l) / len(l)
dev = [(x - mean)*(x - mean) for x in l]
return math.sqrt(sum(dev) / len(l))
# once the dissolve output layer is created, calculates its new attributes values
def calculateFields(self, listKeep, listStats, output):
# get selected layer
index = self.ui.comboLayerList.currentIndex()
legendInterface = self.iface.legendInterface()
listLayers = [layer for layer in legendInterface.layers() if layer.type() == QgsMapLayer.VectorLayer]
selectedLayer = listLayers[index]
# iterates over layer features to get attributes as a list of lists
# uses the processing method so as to get only selected features if this option is set in the processing options
iter = processing.features(selectedLayer)
attrs = [feature.attributes() for feature in iter]
# get all values of the dissolve field (before processing : with duplicate values)
indexDissolveField = self.ui.comboFieldList.currentIndex()
valuesDissolveField = [feature[indexDissolveField] for feature in attrs]
# get unique values for dissolve field, from output (seems more secure than to get it from valuesDissolveField ?)
outputLayer = QgsVectorLayer(output, "name", "ogr")
provider = outputLayer.dataProvider()
fields = provider.fields()
listFieldNames = [field.name() for field in fields]
iter = outputLayer.getFeatures()
uniqueValuesDissolveField = [feature.attributes()[indexDissolveField] for feature in iter]
# initializes list of lists which will contain results (it will have one element per kept field)
listRes = []
# trick for dissolve field, if kept
if listKeep[indexDissolveField] == 2:
listStats [indexDissolveField] = 'First'
# for each kept field
for i in range(len(listFieldNames)):
if listKeep[i] == 2:
# creates list which will contain attribute values for current field, one empty element per unique dissolve field value
listAttrs = [[] for val in range(len(uniqueValuesDissolveField))]
# fill this list with all the current field values corresponding to each dissolve field value
valuesField = [feature[i] for feature in attrs]
for (x,y) in zip(valuesDissolveField, valuesField):
listAttrs[uniqueValuesDissolveField.index(x)].append(y)
# removes any NULL values
listAttrs = [[x for x in l if x] for l in listAttrs]
# for each list in listAttrs, calculates one value according to the chosen stat
# if list is empty (can happen if it contained originally only NULL values), return NULL as a result
if listStats[i] == "Mean":
listAttrs = [sum(y) / len(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Sum":
listAttrs = [sum(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Min":
listAttrs = [min(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Max":
listAttrs = [max(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Count":
listAttrs = [len(y) if y else NULL for y in listAttrs]
elif listStats[i] == "First":
listAttrs = [y[0] if y else NULL for y in listAttrs]
elif listStats[i] == "Last":
listAttrs = [y[-1] if y else NULL for y in listAttrs]
elif listStats[i] == "Median":
listAttrs = [self.median(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Standard deviation":
listAttrs = [self.standard_dev(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Concatenation":
listAttrs = [", ".join(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Uniquification":
listAttrs = [", ".join(set(y)) if y else NULL for y in listAttrs]
# append each field result to listRes
listRes.append(listAttrs)
return listRes
# removes fields from the output which mustn't be kept, and set the other field values
def setAttributes(self, listRes, listKeep, output):
# get indexes of fields to be deleted
listIndexesDel = [i for i in range(len(listKeep)) if listKeep[i] == 0]
# get layer, provider and provider capabilities
outputLayer = QgsVectorLayer(output, "name", "ogr")
provider = outputLayer.dataProvider()
caps = provider.capabilities()
# delete fields to be deleted
if caps & QgsVectorDataProvider.DeleteAttributes:
res = provider.deleteAttributes(listIndexesDel)
outputLayer.updateFields()
# changes other fields attribute values
fields = provider.fields()
nb_fields = len(fields)
outputLayer.startEditing()
for fieldIndex in range(nb_fields):
for fid in range(len(listRes[0])):
outputLayer.changeAttributeValue(fid, fieldIndex, listRes[fieldIndex][fid])
outputLayer.commitChanges()
# add output layer to the map
def addFile(self, output):
layerNameSHP = output.split('/')[-1]
layerName = layerNameSHP.split('.')[0]
layer = QgsVectorLayer(output, layerName, "ogr")
QgsMapLayerRegistry.instance().addMapLayer(layer)
class DissolveWithStatsDialog(QtGui.QDialog, Ui_DissolveWithStats):
def __init__(self, iface):
QtGui.QDialog.__init__(self)
self.iface = iface
# Set up the user interface from Designer.
self.ui = Ui_DissolveWithStats()
self.ui.setupUi(self)
# connect changed index signal in comboLayerList
self.ui.comboLayerList.currentIndexChanged[int].connect(
self.onChangedValueLayer)
# connect changed index signal in comboFieldList
self.ui.comboFieldList.currentIndexChanged[int].connect(
self.onChangedValueField)
# connect click on browse button, to display file dialog for output shapefile
self.ui.outButton.clicked.connect(self.outFile)
# connect OK button to validation function
self.ui.buttonBox.accepted.connect(self.validation)
# connect Cancel button to reject function
self.ui.buttonBox.rejected.connect(self.reject)
# to get all the vector layers names to populate combo box comboLayerList
legendInterface = self.iface.legendInterface()
listLayerName = [
i.name() for i in legendInterface.layers()
if i.type() == QgsMapLayer.VectorLayer
]
# add all these layer names to combo box comboLayerList
self.ui.comboLayerList.addItems(listLayerName)
# populate the field table header
listHeaders = ["name", "type", "keep", "stat"]
self.ui.tableFields.setHorizontalHeaderLabels(listHeaders)
# set column widths for field table
self.ui.tableFields.setColumnWidth(0, 120)
self.ui.tableFields.setColumnWidth(1, 80)
self.ui.tableFields.setColumnWidth(2, 80)
self.ui.tableFields.setColumnWidth(3, 100)
# Run the dialog event loop
result = self.exec_()
# if Cancel was pressed
if result == QtGui.QFileDialog.Rejected:
return
# If OK was pressed
if result == QtGui.QFileDialog.Accepted:
# try:
# get selected layer in combo box comboLayerList
selectedLayerName = self.ui.comboLayerList.currentText()
# get selected field in combo box comboFieldList
selectedFieldName = self.ui.comboFieldList.currentText()
# get fields to keep and stats to calculate
listKeep = []
listStats = []
for row in range(self.ui.tableFields.rowCount()):
listKeep.append(
self.ui.tableFields.cellWidget(row, 2).checkState())
listStats.append(
self.ui.tableFields.cellWidget(row, 3).currentText())
# get output shape
output = self.ui.outShape.text()
# run qgis:dissolve algorithm from processing module
processing.runalg("qgis:dissolve", selectedLayerName, "false",
selectedFieldName, output)
# calculate new field values
listRes = self.calculateFields(listKeep, listStats, output)
# integrates these new values in the output attribute table, and remove fields if necessary
self.setAttributes(listRes, listKeep, output)
# add layer to map if checkBoxAddFile is checked
if self.ui.checkBoxAddFile.checkState() == 2:
self.addFile(output)
# except:
# QtGui.QMessageBox.warning(self, 'Oops', 'Sorry, something went wrong', QtGui.QMessageBox.Ok)
# check if all the dialog parameters are valid
def validation(self):
message = ''
# get list of kept fields
if self.ui.comboLayerList.currentText() != '':
listKeep = []
for row in range(self.ui.tableFields.rowCount()):
listKeep.append(
self.ui.tableFields.cellWidget(row, 2).checkState())
# get selected layer, to test self.ui.outShape.text()
if self.ui.comboLayerList.currentText() != '':
index = self.ui.comboLayerList.currentIndex()
legendInterface = self.iface.legendInterface()
listLayers = [
layer for layer in legendInterface.layers()
if layer.type() == QgsMapLayer.VectorLayer
]
selectedLayer = listLayers[index]
outfile = QgsVectorFileWriter(
self.ui.outShape.text(), "utf-8",
selectedLayer.dataProvider().fields(),
selectedLayer.dataProvider().geometryType(),
selectedLayer.crs())
# if no layer is selected :
if self.ui.comboLayerList.currentText() == '':
message = 'No layer selected\nQGIS must have at least one vector layer loaded'
# if a layer is selected but doesn't have any field
elif self.ui.comboFieldList.currentText() == '':
message = 'No Field selected\nThe selected layer must have at least one field'
# if layer and dissolve field ok, but no fields are checked to be kept
elif 2 not in listKeep:
message = 'Please select at least one field to be kept'
# if no output is selected:
elif self.ui.outShape.text() == '':
message = 'No output layer\nPlease click on Browse button to specify output layer'
# if error in output shapefile path (permission problem for example)
elif (outfile.hasError() != QgsVectorFileWriter.NoError):
message = "Sorry, could not create output shapefile"
# if output does not end in .shp (can happen if user wrote it directly in the QLineEdit box)
elif self.ui.outShape.text()[-4:] not in ['.shp', '.SHP']:
self.ui.outShape.setText(self.ui.outShape.text() + '.shp')
# if something is wrong : show warning message
if message != '':
QtGui.QMessageBox.warning(self, 'Information missing or invalid',
message, QtGui.QMessageBox.Ok)
# if everything is ok : proceed
else:
self.accept()
# if selected value in comboLayerList changes :
# actualize the values in comboFieldList and in tableFields
def onChangedValueLayer(self, index):
# get list of all vector layers in QGIS
legendInterface = self.iface.legendInterface()
listLayers = [
layer for layer in legendInterface.layers()
if layer.type() == QgsMapLayer.VectorLayer
]
# get name of selected layer
provider = listLayers[index].dataProvider()
fields = provider.fields()
listFieldNames = [field.name() for field in fields]
# clear the combo box comboFieldList
self.ui.comboFieldList.clear()
# add all these field names to combo box comboFieldList
self.ui.comboFieldList.addItems(listFieldNames)
# add as many rows in the field table as fields in the shape, minus one
self.ui.tableFields.setRowCount(len(fields))
# populate columns in field table
for i in range(self.ui.tableFields.rowCount()):
# first column : field names
nameitem = QtGui.QTableWidgetItem(fields[i].name())
# the names are not editable
nameitem.setFlags(QtCore.Qt.ItemIsSelectable
| QtCore.Qt.ItemIsEnabled)
self.ui.tableFields.setItem(i, 0, nameitem)
# second column : field types
typeitem = QtGui.QTableWidgetItem(fields[i].typeName())
# the types are not editable
typeitem.setFlags(QtCore.Qt.ItemIsSelectable
| QtCore.Qt.ItemIsEnabled)
self.ui.tableFields.setItem(i, 1, typeitem)
# third column : check box
keepcheckbox = QtGui.QCheckBox()
keepcheckbox.setCheckState(QtCore.Qt.Checked)
keepitem = self.ui.tableFields.setCellWidget(i, 2, keepcheckbox)
# fourth column : stat
listStat = QtGui.QComboBox()
# if field is numeric (works also for PostGIS data, fix by DelazJ, and for int64 and double, fix by A. Ferraton)
if fields[i].type() in [
QtCore.QVariant.Int, QtCore.QVariant.Double, 2, 4, 6
]:
listStat.addItems(statNum)
# if field is not numeric
else:
listStat.addItems(statElse)
statitem = self.ui.tableFields.setCellWidget(i, 3, listStat)
# enable all field lists
self.ui.tableFields.cellWidget(i, 3).setEnabled(True)
# disable list for first field (since it is selected by default when a new layer is selected)
self.ui.tableFields.cellWidget(0, 3).setEnabled(False)
# if selected value in comboFieldList changes :
# re-enable the stats list for ex-selected value, disable it for selected value
def onChangedValueField(self, index):
if self.ui.tableFields.cellWidget(index, 3):
# enable all field lists
for i in range(self.ui.tableFields.rowCount()):
self.ui.tableFields.cellWidget(i, 3).setEnabled(True)
# disable current field list
self.ui.tableFields.cellWidget(index, 3).setEnabled(False)
# creation of the output shapefile
def outFile(self): # by Carson Farmer 2008
# display file dialog for output shapefile
self.ui.outShape.clear()
fileDialog = QtGui.QFileDialog()
fileDialog.setConfirmOverwrite(False)
outName = fileDialog.getSaveFileName(self, "Output Shapefile", ".",
"Shapefiles (*.shp)")
outPath = QtCore.QFileInfo(outName).absoluteFilePath()
if not outPath.upper().endswith(".SHP"):
outPath = outPath + ".shp"
if outName:
self.ui.outShape.clear()
self.ui.outShape.insert(outPath)
# gets the median from a list of numbers
def median(self, l):
# sorts list, get list length
l.sort()
z = len(l)
# if the list has an uneven number of elements
if z % 2:
return l[z / 2]
# if the list has an even number of elements
else:
return (l[(z / 2) - 1] + l[z / 2]) / 2.0
# gets standard deviation from a list of numbers
def standard_dev(self, l):
mean = sum(l) / len(l)
dev = [(x - mean) * (x - mean) for x in l]
return math.sqrt(sum(dev) / len(l))
# once the dissolve output layer is created, calculates its new attributes values
def calculateFields(self, listKeep, listStats, output):
# get selected layer
index = self.ui.comboLayerList.currentIndex()
legendInterface = self.iface.legendInterface()
listLayers = [
layer for layer in legendInterface.layers()
if layer.type() == QgsMapLayer.VectorLayer
]
selectedLayer = listLayers[index]
# iterates over layer features to get attributes as a list of lists
# uses the processing method so as to get only selected features if this option is set in the processing options
iter = processing.features(selectedLayer)
attrs = [feature.attributes() for feature in iter]
# get all values of the dissolve field (before processing : with duplicate values)
indexDissolveField = self.ui.comboFieldList.currentIndex()
valuesDissolveField = [
feature[indexDissolveField] for feature in attrs
]
# get unique values for dissolve field, from output (seems more secure than to get it from valuesDissolveField ?)
outputLayer = QgsVectorLayer(output, "name", "ogr")
provider = outputLayer.dataProvider()
fields = provider.fields()
listFieldNames = [field.name() for field in fields]
iter = outputLayer.getFeatures()
uniqueValuesDissolveField = [
feature.attributes()[indexDissolveField] for feature in iter
]
# initializes list of lists which will contain results (it will have one element per kept field)
listRes = []
# trick for dissolve field, if kept
if listKeep[indexDissolveField] == 2:
listStats[indexDissolveField] = 'First'
# for each kept field
for i in range(len(listFieldNames)):
if listKeep[i] == 2:
# creates list which will contain attribute values for current field, one empty element per unique dissolve field value
listAttrs = [[]
for val in range(len(uniqueValuesDissolveField))]
# fill this list with all the current field values corresponding to each dissolve field value
valuesField = [feature[i] for feature in attrs]
for (x, y) in zip(valuesDissolveField, valuesField):
listAttrs[uniqueValuesDissolveField.index(x)].append(y)
# removes any NULL values
listAttrs = [[x for x in l if x] for l in listAttrs]
# for each list in listAttrs, calculates one value according to the chosen stat
# if list is empty (can happen if it contained originally only NULL values), return NULL as a result
if listStats[i] == "Mean":
listAttrs = [
sum(y) / len(y) if y else NULL for y in listAttrs
]
elif listStats[i] == "Sum":
listAttrs = [sum(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Min":
listAttrs = [min(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Max":
listAttrs = [max(y) if y else NULL for y in listAttrs]
elif listStats[i] == "Count":
listAttrs = [len(y) if y else NULL for y in listAttrs]
elif listStats[i] == "First":
listAttrs = [y[0] if y else NULL for y in listAttrs]
elif listStats[i] == "Last":
listAttrs = [y[-1] if y else NULL for y in listAttrs]
elif listStats[i] == "Median":
listAttrs = [
self.median(y) if y else NULL for y in listAttrs
]
elif listStats[i] == "Standard deviation":
listAttrs = [
self.standard_dev(y) if y else NULL for y in listAttrs
]
elif listStats[i] == "Concatenation":
listAttrs = [
", ".join(y) if y else NULL for y in listAttrs
]
elif listStats[i] == "Uniquification":
listAttrs = [
", ".join(set(y)) if y else NULL for y in listAttrs
]
# append each field result to listRes
listRes.append(listAttrs)
return listRes
# removes fields from the output which mustn't be kept, and set the other field values
def setAttributes(self, listRes, listKeep, output):
# get indexes of fields to be deleted
listIndexesDel = [i for i in range(len(listKeep)) if listKeep[i] == 0]
# get layer, provider and provider capabilities
outputLayer = QgsVectorLayer(output, "name", "ogr")
provider = outputLayer.dataProvider()
caps = provider.capabilities()
# delete fields to be deleted
if caps & QgsVectorDataProvider.DeleteAttributes:
res = provider.deleteAttributes(listIndexesDel)
outputLayer.updateFields()
# changes other fields attribute values
fields = provider.fields()
nb_fields = len(fields)
outputLayer.startEditing()
for fieldIndex in range(nb_fields):
for fid in range(len(listRes[0])):
outputLayer.changeAttributeValue(fid, fieldIndex,
listRes[fieldIndex][fid])
outputLayer.commitChanges()
# add output layer to the map
def addFile(self, output):
layerNameSHP = output.split('/')[-1]
layerName = layerNameSHP.split('.')[0]
layer = QgsVectorLayer(output, layerName, "ogr")
QgsMapLayerRegistry.instance().addMapLayer(layer)