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[processing] [feature] split lines with lines

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bstroebl committed Dec 4, 2014
1 parent 0fa40a6 commit a2c656e6f6d47613491a71ed4e1b491b21a2472b
@@ -118,6 +118,7 @@
from SetRasterStyle import SetRasterStyle
from SelectByExpression import SelectByExpression
from HypsometricCurves import HypsometricCurves
from SplitLinesWithLines import SplitLinesWithLines
# from VectorLayerHistogram import VectorLayerHistogram
# from VectorLayerScatterplot import VectorLayerScatterplot
# from MeanAndStdDevPlot import MeanAndStdDevPlot
@@ -169,6 +170,7 @@ def __init__(self):
PostGISExecuteSQL(), ImportIntoPostGIS(),
SetVectorStyle(), SetRasterStyle(),
SelectByExpression(), HypsometricCurves(),
SplitLinesWithLines()
# ------ raster ------
# CreateConstantRaster(),
# ------ graphics ------
@@ -0,0 +1,140 @@
# -*- coding: utf-8 -*-

"""
***************************************************************************
SplitLines.py
---------------------
Date : November 2014
Copyright : (C) 2014 by Bernhard Ströbl
Email : bernhard dot stroebl at jena dot 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__ = 'November 2014'
__copyright__ = '(C) 2014, Bernhard Ströbl'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.outputs import OutputVector
from processing.tools import dataobjects
from processing.tools import vector


class SplitLinesWithLines(GeoAlgorithm):

INPUT_A = 'INPUT_A'
INPUT_B = 'INPUT_B'

OUTPUT = 'OUTPUT'

def defineCharacteristics(self):
self.name = 'Split lines with lines'
self.group = 'Vector overlay tools'
self.addParameter(ParameterVector(self.INPUT_A, 'Input layer',
[ParameterVector.VECTOR_TYPE_LINE]))
self.addParameter(ParameterVector(self.INPUT_B, 'Split layer',
[ParameterVector.VECTOR_TYPE_LINE]))

self.addOutput(OutputVector(self.OUTPUT, 'Split lines'))

def processAlgorithm(self, progress):
layerA = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT_A))
layerB = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT_B))

fieldList = layerA.pendingFields()

writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fieldList,
QGis.WKBLineString, layerA.dataProvider().crs())

spatialIndex = vector.spatialindex(layerB)

inFeatA = QgsFeature()
inFeatB = QgsFeature()
outFeat = QgsFeature()
inGeom = QgsGeometry()
splitGeom = QgsGeometry()

features = vector.features(layerA)
current = 0
total = 100.0 / float(len(features))

for inFeatA in features:
inGeom = inFeatA.geometry()
attrsA = inFeatA.attributes()
outFeat.setAttributes(attrsA)
inLines = [inGeom]
lines = spatialIndex.intersects(inGeom.boundingBox())

if len(lines) > 0: #hasIntersections
splittingLines = []

for i in lines:
request = QgsFeatureRequest().setFilterFid(i)
inFeatB = layerB.getFeatures(request).next()
splitGeom = QgsGeometry(inFeatB.geometry())

if inGeom.intersects(splitGeom):
splittingLines.append(splitGeom)

if len(splittingLines) > 0:
for splitGeom in splittingLines:
splitterPList = vector.extractPoints(splitGeom)
outLines = []

while len(inLines) > 0:
inGeom = inLines.pop()
inPoints = vector.extractPoints(inGeom)

if inGeom.intersects(splitGeom):
try:
result, newGeometries, topoTestPoints = inGeom.splitGeometry(splitterPList, False)
except:
QgsMessageLog.logMessage("exception")
result = 1

# splitGeometry: If there are several intersections
# between geometry and splitLine, only the first one is considered.
if result == 0: #split occured

if inPoints == vector.extractPoints(inGeom):
# bug in splitGeometry: sometimes it returns 0 but
# the geometry is unchanged
outLines.append(inGeom)
else:
inLines.append(inGeom)

for aNewGeom in newGeometries:
inLines.append(aNewGeom)
else:
outLines.append(inGeom)
else:
outLines.append(inGeom)

inLines = outLines


for aLine in inLines:
outFeat.setGeometry(aLine)
writer.addFeature(outFeat)

current += 1
progress.setPercentage(int(current * total))

del writer
@@ -0,0 +1,29 @@
SPLIT LINES WITH LINES
=======================

Description
-----------
This algorithm splits the features of a line layer with the lines of another line layer.

Parameters
----------

- ``Input layer[Vector]``:line layer
- ``Split layer[Vector]``:line layer

Outputs
-------

- ``Output layer[Vector]``: resulting layer

See also
---------


Console usage
-------------


::

processing.runalg('qgis:splitlineswithlines', input_lines, split_lines, output)

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