# -*- coding: utf-8 -*-
"""
***************************************************************************
Eliminate.py
---------------------
Date : August 2012
Copyright : (C) 2013 by Bernhard Str�bl
Email : bernhard.stroebl@jena.de
***************************************************************************
* *
* 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__ = 'Bernhard Ströbl'
__date__ = 'September 2013'
__copyright__ = '(C) 2013, Bernhard Ströbl'
# 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 processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import \
GeoAlgorithmExecutionException
from processing.core.ProcessingLog import ProcessingLog
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterBoolean
from processing.core.parameters import ParameterTableField
from processing.core.parameters import ParameterString
from processing.core.parameters import ParameterSelection
from processing.core.outputs import OutputVector
from processing.tools import dataobjects
class Eliminate(GeoAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
MODE = 'MODE'
KEEPSELECTION = 'KEEPSELECTION'
ATTRIBUTE = 'ATTRIBUTE'
COMPARISONVALUE = 'COMPARISONVALUE'
COMPARISON = 'COMPARISON'
MODES = ['Largest area', 'Smallest Area', 'Largest common boundary']
MODE_LARGEST_AREA = 0
MODE_SMALLEST_AREA = 1
MODE_BOUNDARY = 2
def defineCharacteristics(self):
self.name = 'Eliminate sliver polygons'
self.group = 'Vector geometry tools'
self.addParameter(ParameterVector(self.INPUT, 'Input layer',
[ParameterVector.VECTOR_TYPE_POLYGON]))
self.addParameter(ParameterBoolean(self.KEEPSELECTION,
'Use current selection in input layer (works only ' + \
'if called from toolbox)', False))
self.addParameter(ParameterTableField(self.ATTRIBUTE,
'Selection attribute', self.INPUT))
self.comparisons = [
'==',
'!=',
'>',
'>=',
'<',
'<=',
'begins with',
'contains',
]
self.addParameter(ParameterSelection(self.COMPARISON, 'Comparison',
self.comparisons, default=0))
self.addParameter(ParameterString(self.COMPARISONVALUE, 'Value',
default='0'))
self.addParameter(ParameterSelection(self.MODE,
'Merge selection with the neighbouring polygon with the ',
self.MODES))
self.addOutput(OutputVector(self.OUTPUT, 'Cleaned layer'))
def processAlgorithm(self, progress):
inLayer = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT))
boundary = self.getParameterValue(self.MODE) == self.MODE_BOUNDARY
smallestArea = self.getParameterValue(self.MODE) == self.MODE_SMALLEST_AREA
keepSelection = self.getParameterValue(self.KEEPSELECTION)
if not keepSelection:
# Make a selection with the values provided
attribute = self.getParameterValue(self.ATTRIBUTE)
comparison = self.comparisons[
self.getParameterValue(self.COMPARISON)]
comparisonvalue = self.getParameterValue(self.COMPARISONVALUE)
selectindex = inLayer.dataProvider().fieldNameIndex(attribute)
selectType = inLayer.dataProvider().fields()[selectindex].type()
selectionError = False
if selectType == 2:
try:
y = int(comparisonvalue)
except ValueError:
selectionError = True
msg = 'Cannot convert "' + unicode(comparisonvalue) \
+ '" to integer'
elif selectType == 6:
try:
y = float(comparisonvalue)
except ValueError:
selectionError = True
msg = 'Cannot convert "' + unicode(comparisonvalue) \
+ '" to float'
elif selectType == 10:
# 10: string, boolean
try:
y = unicode(comparisonvalue)
except ValueError:
selectionError = True
msg = 'Cannot convert "' + unicode(comparisonvalue) \
+ '" to unicode'
elif selectType == 14:
# date
dateAndFormat = comparisonvalue.split(' ')
if len(dateAndFormat) == 1:
# QtCore.QDate object
y = QLocale.system().toDate(dateAndFormat[0])
if y.isNull():
msg = 'Cannot convert "' + unicode(dateAndFormat) \
+ '" to date with system date format ' \
+ QLocale.system().dateFormat()
elif len(dateAndFormat) == 2:
y = QDate.fromString(dateAndFormat[0], dateAndFormat[1])
if y.isNull():
msg = 'Cannot convert "' + unicode(dateAndFormat[0]) \
+ '" to date with format string "' \
+ unicode(dateAndFormat[1] + '". ')
else:
y = QDate()
msg = ''
if y.isNull():
# Conversion was unsuccessfull
selectionError = True
msg += 'Enter the date and the date format, e.g. \
"07.26.2011" "MM.dd.yyyy".'
if (comparison == 'begins with' or comparison == 'contains') \
and selectType != 10:
selectionError = True
msg = '"' + comparison \
+ '" can only be used with string fields'
selected = []
if selectionError:
raise GeoAlgorithmExecutionException(
'Error in selection input: ' + msg)
else:
for feature in inLayer.getFeatures():
aValue = feature.attributes()[selectindex]
if aValue is None:
continue
if selectType == 2:
x = int(aValue)
elif selectType == 6:
x = float(aValue)
elif selectType == 10:
# 10: string, boolean
x = unicode(aValue)
elif selectType == 14:
# date
x = aValue # should be date
match = False
if comparison == '==':
match = x == y
elif comparison == '!=':
match = x != y
elif comparison == '>':
match = x > y
elif comparison == '>=':
match = x >= y
elif comparison == '<':
match = x < y
elif comparison == '<=':
match = x <= y
elif comparison == 'begins with':
match = x.startswith(y)
elif comparison == 'contains':
match = x.find(y) >= 0
if match:
selected.append(feature.id())
inLayer.setSelectedFeatures(selected)
if inLayer.selectedFeatureCount() == 0:
ProcessingLog.addToLog(ProcessingLog.LOG_WARNING,
self.commandLineName()
+ '(No selection in input layer "'
+ self.getParameterValue(self.INPUT) + '")')
# Keep references to the features to eliminate
featToEliminate = []
for aFeat in inLayer.selectedFeatures():
featToEliminate.append(aFeat)
# Delete all features to eliminate in inLayer (we won't save this)
inLayer.startEditing()
inLayer.deleteSelectedFeatures()
# ANALYZE
if len(featToEliminate) > 0: # Prevent zero division
start = 20.00
add = 80.00 / len(featToEliminate)
else:
start = 100
progress.setPercentage(start)
madeProgress = True
# We go through the list and see if we find any polygons we can
# merge the selected with. If we have no success with some we
# merge and then restart the whole story.
while madeProgress: # Check if we made any progress
madeProgress = False
featNotEliminated = []
# Iterate over the polygons to eliminate
for i in range(len(featToEliminate)):
feat = featToEliminate.pop()
geom2Eliminate = feat.geometry()
bbox = geom2Eliminate.boundingBox()
fit = inLayer.getFeatures(
QgsFeatureRequest().setFilterRect(bbox))
mergeWithFid = None
mergeWithGeom = None
max = 0
min = -1
selFeat = QgsFeature()
while fit.nextFeature(selFeat):
selGeom = selFeat.geometry()
if geom2Eliminate.intersects(selGeom):
# We have a candidate
iGeom = geom2Eliminate.intersection(selGeom)
if boundary:
selValue = iGeom.length()
else:
# area. We need a common boundary in
# order to merge
if 0 < iGeom.length():
selValue = selGeom.area()
else:
selValue = -1
if -1 != selValue:
useThis = True
if smallestArea:
if -1 == min:
min = selValue
else:
if selValue < min:
min = selValue
else:
useThis = False
else:
if selValue > max:
max = selValue
else:
useThis = False
if useThis:
mergeWithFid = selFeat.id()
mergeWithGeom = QgsGeometry(selGeom)
# End while fit
if mergeWithFid is not None:
# A successful candidate
newGeom = mergeWithGeom.combine(geom2Eliminate)
if inLayer.changeGeometry(mergeWithFid, newGeom):
madeProgress = True
else:
raise GeoAlgorithmExecutionException(
'Could not replace geometry of feature ' + \
'with id %s' % mergeWithFid)
start = start + add
progress.setPercentage(start)
else:
featNotEliminated.append(feat)
# End for featToEliminate
featToEliminate = featNotEliminated
# End while
# Create output
provider = inLayer.dataProvider()
output = self.getOutputFromName(self.OUTPUT)
writer = output.getVectorWriter(provider.fields(),
provider.geometryType(), inLayer.crs())
# Write all features that are left over to output layer
iterator = inLayer.getFeatures()
for feature in iterator:
writer.addFeature(feature)
# Leave inLayer untouched
inLayer.rollBack()
for feature in featNotEliminated:
writer.addFeature(feature)