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[processing] add points displacement algorithm

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alexbruy committed Sep 13, 2013
1 parent 3ecaa5f commit 395dc747e003a1079b424101c0650c6f8cca2bb8
@@ -86,6 +86,8 @@
from processing.algs.CreateConstantRaster import CreateConstantRaster
from processing.algs.PointsLayerFromTable import PointsLayerFromTable

from processing.algs.PointsDisplacement import PointsDisplacement

#from processing.algs.VectorLayerHistogram import VectorLayerHistogram
#from processing.algs.VectorLayerScatterplot import VectorLayerScatterplot
#from processing.algs.MeanAndStdDevPlot import MeanAndStdDevPlot
@@ -134,10 +136,12 @@ def __init__(self):
PointsLayerFromTable(), StatisticsByCategories(), Polygonize(),
# ------ raster ------
#CreateConstantRaster(),
RasterLayerStatistics()
RasterLayerStatistics(),
# ------ graphics ------
#VectorLayerHistogram(), VectorLayerScatterplot(), RasterLayerHistogram(),
#MeanAndStdDevPlot(), BarPlot(), PolarPlot()
# ------ vector ------
PointsDisplacement()
]

def initializeSettings(self):
@@ -0,0 +1,121 @@
# -*- coding: utf-8 -*-

"""
***************************************************************************
PointsDisplacement.py
---------------------
Date : July 2013
Copyright : (C) 2013 by Alexander Bruy
Email : alexander dot bruy at gmail dot com
***************************************************************************
* *
* 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__ = 'Alexander Bruy'
__date__ = 'July 2013'
__copyright__ = '(C) 2013, Alexander Bruy'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'

import math

from PyQt4.QtCore import *

from qgis.core import *

from sextante.core.GeoAlgorithm import GeoAlgorithm
from sextante.core.QGisLayers import QGisLayers

from sextante.parameters.ParameterVector import ParameterVector
from sextante.parameters.ParameterNumber import ParameterNumber
from sextante.parameters.ParameterBoolean import ParameterBoolean
from sextante.outputs.OutputVector import OutputVector

class PointsDisplacement(GeoAlgorithm):

INPUT_LAYER = "INPUT_LAYER"
DISTANCE = "DISTANCE"
HORIZONTAL = "HORIZONTAL"
OUTPUT_LAYER = "OUTPUT_LAYER"

def defineCharacteristics(self):
self.name = "Points displacement"
self.group = "Vector geometry tools"

self.addParameter(ParameterVector(self.INPUT_LAYER, "Input layer", ParameterVector.VECTOR_TYPE_POINT))
self.addParameter(ParameterNumber(self.DISTANCE, "Displacement distance", 0.00001, 999999999.999990, 0.00015))
self.addParameter(ParameterBoolean(self.HORIZONTAL, "Horizontal distribution for two point case"))
self.addOutput(OutputVector(self.OUTPUT_LAYER, "Output layer"))

def processAlgorithm(self, progress):
radius = self.getParameterValue(self.DISTANCE)
horizontal = self.getParameterValue(self.HORIZONTAL)
output = self.getOutputFromName(self.OUTPUT_LAYER)

layer = QGisLayers.getObjectFromUri(self.getParameterValue(self.INPUT_LAYER))

provider = layer.dataProvider()
writer = output.getVectorWriter(provider.fields(), provider.geometryType(), provider.crs())

features = QGisLayers.features(layer)

current = 0
total = 100.0 / len(features)

duplicates = dict()
for f in features:
wkt = f.geometry().exportToWkt()
if wkt not in duplicates:
duplicates[wkt] = [f.id()]
else:
duplicates[wkt].extend([f.id()])

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

current = 0
total = 100.0 / len(duplicates)
progress.setPercentage(0)

fullPerimeter = 2 * math.pi

request = QgsFeatureRequest()
for geom, fids in duplicates.iteritems():
count = len(fids)
if count == 1:
f = layer.getFeatures(request.setFilterFid(fids[0])).next()
writer.addFeature(f)
else:
angleStep = fullPerimeter / count
if count == 2 and horizontal:
currentAngle = math.pi / 2
else:
currentAngle = 0

old_point = QgsGeometry.fromWkt(geom).asPoint()
for fid in fids:
sinusCurrentAngle = math.sin(currentAngle)
cosinusCurrentAngle = math.cos(currentAngle)
dx = radius * sinusCurrentAngle
dy = radius * cosinusCurrentAngle

f = layer.getFeatures(request.setFilterFid(fid)).next()

new_point = QgsPoint(old_point.x() + dx, old_point.y() + dy)
out_feature = QgsFeature()
out_feature.setGeometry(QgsGeometry.fromPoint(new_point))
out_feature.setAttributes(f.attributes())

writer.addFeature(out_feature)
currentAngle += angleStep

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

del writer

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