refactor Hub distance alg

python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py

@@ -80,6 +80,7 @@
 from mmqgisx.SelectByAttribute import SelectByAttribute
 from mmqgisx.Grid import Grid
 from mmqgisx.Gridify import Gridify
+from mmqgisx.HubDistance import HubDistance
 
 from ConcaveHull import ConcaveHull
 from Polygonize import Polygonize
@@ -146,7 +147,7 @@ def __init__(self):
                         # ------ mmqgisx ------
                         DeleteColumn(), DeleteDuplicateGeometries(),
                         TextToFloat(), ExtractByAttribute(),
-                        SelectByAttribute(), Grid(), Gridify(),
+                        SelectByAttribute(), Grid(), Gridify(), HubDistance(),
                         #mmqgisx_delete_duplicate_geometries_algorithm(),
                         #mmqgisx_geometry_convert_algorithm(),
                         #mmqgisx_grid_algorithm(),

python/plugins/processing/algs/qgis/mmqgisx/HubDistance.py

@@ -0,0 +1,160 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    Gridify.py
+    ---------------------
+    Date                 : May 2010
+    Copyright            : (C) 2010 by Michael Minn
+    Email                : pyqgis at michaelminn 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__ = 'Michael Minn'
+__date__ = 'May 2010'
+__copyright__ = '(C) 2010, Michael Minn'
+
+# 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.parameters import ParameterVector
+from processing.core.parameters import ParameterTableField
+from processing.core.parameters import ParameterSelection
+from processing.core.outputs import OutputVector
+
+from processing.tools import dataobjects, vector
+
+class HubDistance(GeoAlgorithm):
+    POINTS = 'POINTS'
+    HUBS = 'HUBS'
+    FIELD = 'FIELD'
+    GEOMETRY = 'GEOMETRY'
+    UNIT = 'UNIT'
+    OUTPUT = 'OUTPUT'
+
+    GEOMETRIES = ['Point',
+                  'Line to hub'
+                 ]
+
+    UNITS = ['Meters',
+             'Feet',
+             'Miles',
+             'Kilometers',
+             'Layer units'
+            ]
+
+    def defineCharacteristics(self):
+        self.name = 'Distance to nearest hub'
+        self.group = 'Vector analysis tools'
+
+        self.addParameter(ParameterVector(self.POINTS,
+            'Source points layer', [ParameterVector.VECTOR_TYPE_ANY]))
+        self.addParameter(ParameterVector(self.HUBS,
+            'Destination hubs layer', [ParameterVector.VECTOR_TYPE_ANY]))
+        self.addParameter(ParameterTableField(
+            self.FIELD, 'Hub layer name attribute', self.HUBS))
+        self.addParameter(ParameterSelection(
+            self.GEOMETRY, 'Output shape type', self.GEOMETRIES))
+        self.addParameter(ParameterSelection(
+            self.UNIT, 'Measurement unit', self.UNITS))
+
+        self.addOutput(OutputVector(self.OUTPUT, 'Output'))
+
+    def processAlgorithm(self, progress):
+        layerPoints = dataobjects.getObjectFromUri(
+            self.getParameterValue(self.POINTS))
+        layerHubs = dataobjects.getObjectFromUri(
+            self.getParameterValue(self.HUBS))
+        fieldName = self.getParameterValue(self.FIELD)
+
+        addLines = self.getParameterValue(self.GEOMETRY)
+        units = self.UNITS[self.getParameterValue(self.UNIT)]
+
+        if layerPoints.source() == layerHubs.source():
+            raise GeoAlgorithmExecutionException(
+                'Same layer given for both hubs and spokes')
+
+        geomType = QGis.WKBPoint
+        if addLines:
+            geomType = QGis.WKBLineString
+
+        fields = layerPoints.pendingFields()
+        fields.append(QgsField('HubName', QVariant.String))
+        fields.append(QgsField('HubDist', QVariant.Double))
+
+        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
+            fields, geomType, layerPoints.crs())
+
+        # Create array of hubs in memory
+        hubs = []
+        features = vector.features(layerHubs)
+        for f in features:
+            hubs.append(Hub(f.geometry().boundingBox().center(),
+                            unicode(f[fieldName])))
+
+        distance = QgsDistanceArea()
+        distance.setSourceCrs(layerPoints.crs().srsid())
+        distance.setEllipsoidalMode(True)
+
+        # Scan source points, find nearest hub, and write to output file
+        features = vector.features(layerPoints)
+        count = len(features)
+        total = 100.0 / float(count)
+        for count, f in enumerate(features):
+            src = f.geometry().boundingBox().center()
+
+            closest = hubs[0]
+            hubDist = distance.measureLine(src, closest.point)
+
+            for hub in hubs:
+                dist = distance.measureLine(src, hub.point)
+                if dist < hubDist:
+                    closest = hub
+                    hubDist = dist
+
+            attributes = f.attributes()
+            attributes.append(closest.name)
+            if units == 'Feet':
+                attributes.append(hubDist * 3.2808399)
+            elif units == 'Miles':
+                attributes.append(hubDist * 0.000621371192)
+            elif units == 'Kilometers':
+                attributes.append(hubDist / 1000.0)
+            elif units != 'Meters':
+                attributes.append(sqrt(
+                    pow(source.x() - closest.point.x(), 2.0) +
+                    pow(source.y() - closest.point.y(), 2.0)))
+            else:
+                attributes.append(hubDist)
+
+            feat = QgsFeature()
+            feat.setAttributes(attributes)
+
+            if geomType == QGis.WKBPoint:
+                feat.setGeometry(QgsGeometry.fromPoint(src))
+            else:
+                feat.setGeometry(QgsGeometry.fromPolyline([src, closest.point]))
+
+            writer.addFeature(feat)
+            progress.setPercentage(int(count * total))
+
+        del writer
+
+
+class Hub:
+    def __init__(self, point, name):
+        self.point = point
+        self.name = name