Ihre Frage hat mich neugierig gemacht.
Diese Lösung funktioniert nur für QGIS 2.x in der Python-Konsole
Wie in meinem Kommentar hier erwähnt, ist meine Idee, den Linienbogen mit Python zu erstellen.
Ich habe zwei Punktebenen:
ich. Einer, der das Kapital hält (id, Kapital)
ii. Einer hält die Städte (Ausweis, Stadt, Pendler)
Die Anzahl der Pendler wird "in Banknoten aufgeteilt" und dies sind die Linien, die den Bogen bilden. 371 Pendler sind also eine Kombination aus 3x100, 1x50, 2x10 und 1x1 und insgesamt 7 Banknoten. Anschließend werden die Linien durch ein regelbasiertes Styling gestaltet.
Hier ist der Code:
from qgis.gui import *
from qgis.utils import *
from qgis.core import *
from PyQt4 import QtGui, uic
from PyQt4.QtGui import *
from PyQt4.QtCore import *
for lyr in QgsMapLayerRegistry.instance().mapLayers().values():
if lyr.name() == "capital":
capital_layer = lyr
for lyr in QgsMapLayerRegistry.instance().mapLayers().values():
if lyr.name() == "town":
town_layer = lyr
# creating the memory layer
d_lyr = QgsVectorLayer('LineString', 'distance', 'memory')
QgsMapLayerRegistry.instance().addMapLayer(d_lyr)
prov = d_lyr.dataProvider()
prov.addAttributes( [ QgsField("id", QVariant.Int), QgsField("banknote",QVariant.Int)])
# function to create the banknotes
def banknoteOutput(number):
number_list = []
number_list.append(number)
banknote_count = []
temp_list = []
banknote_list = []
for n in number_list:
total_sum = 0
total = int(n/100)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 100])
n = n-(total*100)
total = int(n/50)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 50])
n = n-(total*50)
total = int(n/10)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 10])
n = n-(total*10)
total = int(n/5)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 5])
n = n-(total*5)
total = int(n/1)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 1])
for i in banknote_count:
temp_list.append(i*i[0])
banknote_list = [item for sublist in temp_list for item in sublist][1::2]
return banknote_list
# creating lines with the amount of banknotes
for capital in capital_layer.getFeatures():
for town in town_layer.getFeatures():
commuter_splitting = banknoteOutput(town['commuters'])
for i,banknote in enumerate(commuter_splitting):
angle = 2
distance = QgsDistanceArea()
distance.measureLine(capital.geometry().asPoint(), town.geometry().asPoint())
vect = QgsFeature()
vect.setGeometry(QgsGeometry.fromPolyline([capital.geometry().asPoint(), town.geometry().asPoint()]))
vect.geometry().rotate(0+(i*angle), capital.geometry().asPoint())
vect.setAttributes([int(town["id"]), int(banknote)])
prov.addFeatures([vect])
d_lyr.updateExtents()
d_lyr.triggerRepaint()
d_lyr.updateFields()
Das Ergebnis könnte folgendermaßen aussehen:
UPDATE: Unterscheidung männlich / weiblich
Ergebnisse in 4 Speicherschicht.
from qgis.gui import *
from qgis.utils import *
from qgis.core import *
from PyQt4 import QtGui, uic
from PyQt4.QtGui import *
from PyQt4.QtCore import *
for lyr in QgsMapLayerRegistry.instance().mapLayers().values():
if lyr.name() == "capital":
capital_layer = lyr
for lyr in QgsMapLayerRegistry.instance().mapLayers().values():
if lyr.name() == "town":
town_layer = lyr
# function to create the banknotes
def banknoteOutput(number):
number_list = []
number_list.append(number)
banknote_count = []
temp_list = []
banknote_list = []
for n in number_list:
total_sum = 0
total = int(n/100)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 100])
n = n-(total*100)
total = int(n/50)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 50])
n = n-(total*50)
total = int(n/10)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 10])
n = n-(total*10)
total = int(n/5)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 5])
n = n-(total*5)
total = int(n/1)
total_sum = total_sum + total
if total > 0:
banknote_count.append([total, 1])
for i in banknote_count:
temp_list.append(i*i[0])
banknote_list = [item for sublist in temp_list for item in sublist][1::2]
return banknote_list
# creating the male memory layer
cmt_male = QgsVectorLayer('LineString', 'Commuters_Male', 'memory')
QgsMapLayerRegistry.instance().addMapLayer(cmt_male)
prov_male = cmt_male.dataProvider()
prov_male.addAttributes( [ QgsField("id", QVariant.Int), QgsField("banknote",QVariant.Int)])
# creating the male polygon memory layer
cmt_male_polygon = QgsVectorLayer('Polygon', 'Commuters_Male_Poly', 'memory')
QgsMapLayerRegistry.instance().addMapLayer(cmt_male_polygon)
prov_cmt_male_polygon = cmt_male_polygon.dataProvider()
prov_cmt_male_polygon.addAttributes( [ QgsField("id", QVariant.Int), QgsField("banknote",QVariant.Int)])
# creating lines with the amount of banknotes
for capital in capital_layer.getFeatures():
for town in town_layer.getFeatures():
commuter_splitting = banknoteOutput(town['cmt_male'])
points = []
for i,banknote in enumerate(reversed(commuter_splitting)):
angle = 2
distance = QgsDistanceArea()
distance.measureLine(capital.geometry().asPoint(), town.geometry().asPoint())
vect = QgsFeature()
vect.setGeometry(QgsGeometry.fromPolyline([capital.geometry().asPoint(), town.geometry().asPoint()]))
vect.geometry().rotate(0+(i*angle), capital.geometry().asPoint())
vect.setAttributes([int(town["id"]), int(banknote)])
points.append(vect.geometry().asPolyline()[1])
prov_male.addFeatures([vect])
polygon = QgsFeature()
points.insert(0,capital.geometry().asPoint())
points.insert(len(points),capital.geometry().asPoint())
polygon.setGeometry(QgsGeometry.fromPolygon([points]))
polygon.setAttributes([1, 2])
prov_cmt_male_polygon.addFeatures([polygon])
cmt_male.updateExtents()
cmt_male.triggerRepaint()
cmt_male.updateFields()
cmt_male_polygon.updateExtents()
cmt_male_polygon.triggerRepaint()
cmt_male_polygon.updateFields()
# creating the female memory layer
cmt_female = QgsVectorLayer('LineString', 'Commuters_Female', 'memory')
QgsMapLayerRegistry.instance().addMapLayer(cmt_female)
prov_female = cmt_female.dataProvider()
prov_female.addAttributes( [ QgsField("id", QVariant.Int), QgsField("banknote",QVariant.Int)])
# creating the female polygon memory layer
cmt_female_polygon = QgsVectorLayer('Polygon', 'Commuters_Female_Poly', 'memory')
QgsMapLayerRegistry.instance().addMapLayer(cmt_female_polygon)
prov_cmt_female_polygon = cmt_female_polygon.dataProvider()
prov_cmt_female_polygon.addAttributes( [ QgsField("id", QVariant.Int), QgsField("banknote",QVariant.Int)])
# creating lines with the amount of banknotes
for capital in capital_layer.getFeatures():
for town in town_layer.getFeatures():
commuter_splitting = banknoteOutput(town['cmt_female'])
points = []
for i,banknote in enumerate(commuter_splitting):
angle = 2
distance = QgsDistanceArea()
distance.measureLine(capital.geometry().asPoint(), town.geometry().asPoint())
vect = QgsFeature()
vect.setGeometry(QgsGeometry.fromPolyline([capital.geometry().asPoint(), town.geometry().asPoint()]))
vect.geometry().rotate(-angle-(i*angle), capital.geometry().asPoint())
vect.setAttributes([int(town["id"]), int(banknote)])
points.append(vect.geometry().asPolyline()[1])
prov_female.addFeatures([vect])
polygon = QgsFeature()
points.insert(0,capital.geometry().asPoint())
points.insert(len(points),capital.geometry().asPoint())
polygon.setGeometry(QgsGeometry.fromPolygon([points]))
polygon.setAttributes([1, 2])
prov_cmt_female_polygon.addFeatures([polygon])
cmt_female.updateExtents()
cmt_female.triggerRepaint()
cmt_female.updateFields()
cmt_female_polygon.updateExtents()
cmt_female_polygon.triggerRepaint()
cmt_female_polygon.updateFields()
Das Ergebnis könnte folgendermaßen aussehen:
Eine Sache, die aus kartografischer Sicht nicht ideal ist:
Die Größe eines Linienbogens kann auf den ersten Blick irritierend sein, da ein größerer Bogen mehr Pendler darstellen könnte. Ein Bogen kann mit weniger Pendlern (289 Pendler / 11 Banknoten) größer sein als ein anderer mit mehr Pendlern (311 Pendler / 5 Banknoten).
