2017-06-10 09:41:05 +01:00

97 lines
3.6 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
v_net.py
--------
Date : December 2015
Copyright : (C) 2015 by Médéric Ribreux
Email : medspx at medspx dot fr
***************************************************************************
* *
* 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 Python module handles pre-treatment operations for v.net.* GRASS7 modules.
Before using a v.net module you often have to incorporate a points layer into
the network vector map.
"""
__author__ = 'Médéric Ribreux'
__date__ = 'December 2015'
__copyright__ = '(C) 2015, Médéric Ribreux'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import os
from copy import deepcopy
def incorporatePoints(alg, parameters, pointLayerName=u'points', networkLayerName=u'input'):
"""
incorporate points with lines to form a GRASS network
"""
new_parameters = deepcopy(parameters)
# Create an intermediate GRASS layer which is the combination of network + centers
intLayer = alg.getTempFilename()
# Grab the point layer and delete this parameter (not used by v.net.alloc)
pointLayer = new_parameters[pointLayerName]
if pointLayer:
pointLayer = alg.exportedLayers[pointLayer]
new_parameters['points'] = pointLayer
# Grab the network layer and tell to v.net.alloc to use the temp layer instead
lineLayer = new_parameters[networkLayerName]
if lineLayer:
lineLayer = alg.exportedLayers[lineLayer]
new_parameters[networkLayerName] = lineLayer
threshold = parameters['threshold']
# Create the v.net connect command for point layer integration
command = u"v.net -s input={} points={} out={} op=connect threshold={}".format(
lineLayer, pointLayer, intLayer, threshold)
alg.commands.append(command)
# Connect the point layer database to the layer 2 of the network
command = u"v.db.connect -o map={} table={} layer=2".format(intLayer, pointLayer)
alg.commands.append(command)
alg.processCommand(new_parameters)
def variableOutput(alg, params, nocats=True):
""" Handle variable data output for v.net modules:
params is like:
{ u"output": [u"point", 1], # One output of type point from layer 1
u"output2": [u"line", 1], # One output of type line from layer 1
u"output3: [u"point", 2] # one output of type point from layer 2
}
"""
# Build the v.out.ogr commands
for outputName, typeList in list(params.items()):
if not isinstance(typeList, list):
continue
out = alg.getOutputValue(outputName)
command = u"v.out.ogr {} type={} layer={} -s -e input={} output=\"{}\" format=ESRI_Shapefile output_layer={} --overwrite".format(
u"" if typeList[0] == u"line" and nocats else u"-c",
typeList[0],
typeList[1],
alg.exportedLayers[out],
os.path.dirname(out),
os.path.basename(out)[:-4]
)
alg.commands.append(command)
alg.outputCommands.append(command)