implement threshold. add austria example.

README.md

@@ -42,7 +42,8 @@ D'Hondt (Jefferson) method
 
 which is indeed the [official result](https://www.bmi.gv.at/412/Europawahlen/Europawahl_2019).
 
-Another example can be found in [example.py](example.py).
+Another example can be found in [examples/example.py](examples/example.py).
+An example with the Austrian National Council elections can be found in [examples/austria_examples.py](examples/austria_examples.py)
 
 ## References
 

apportionment.py

@@ -4,22 +4,39 @@ import math
 from fractions import Fraction
 
 
-def method(method, votes, seats, parties=string.letters,
+def method(method, votes, seats, parties=string.letters, threshold=None,
            verbose=True):
+    filtered_votes = apply_threshold(votes, threshold)
     if method == "quota":
-        return quota(votes, seats, parties, verbose)
+        return quota(filtered_votes, seats, parties, verbose)
     elif method in ["lrm", "hamilton", "largest_remainder"]:
-        return largest_remainder(votes, seats, parties, verbose)
+        return largest_remainder(filtered_votes, seats, parties, verbose)
     elif method in ["dhondt", "jefferson", "saintelague", "webster",
                     "huntington", "hill", "adams", "dean",
                     "smallestdivisor", "harmonicmean", "equalproportions",
                     "majorfractions", "greatestdivisors"]:
-        return divisor(votes, seats, method, parties, verbose)
+        return divisor(filtered_votes, seats, method, parties, verbose)
     else:
         raise NotImplementedError("apportionment method " + method +
                                   " not known")
 
 
+def apply_threshold(votes, threshold):
+    """Sets vote counts to 0 if threshold is not met."""
+    if threshold is not None:
+        v = []
+        combined_votes = sum(votes)
+        min_votes = combined_votes * threshold
+        for vote in votes:
+            if vote < min_votes:
+                v.append(0)
+            else:
+                v.append(vote)
+        return v
+    else:
+        return votes
+
+
 def __print_results(representatives, parties):
     for i in range(len(representatives)):
         print("  "+str(parties[i])+": "+str(representatives[i]))

examples/austria_examples.py

@@ -0,0 +1,17 @@
+from __future__ import print_function
+import sys
+sys.path.insert(0, '..')
+import apportionment
+
+with open("./nr_wahlen.txt", "r") as f:
+
+    for line in f:
+        result = eval(line)
+        print(result[0])
+        print(apportionment.method("dhondt", result[2],
+                                   sum(result[3]),
+                                   parties=result[1],
+                                   threshold=.04,
+                                   verbose=False))
+        # actual results
+        print(result[3])

examples/example.py

@@ -1,4 +1,6 @@
 from __future__ import print_function
+import sys
+sys.path.insert(0, '..')
 import apportionment
 
 

examples/nr_wahlen.txt

@@ -0,0 +1,9 @@
+(2019,["ÖVP", "SPÖ", "FPÖ", "NEOS", "JETZT", "GRÜNE", "KPÖ", "WANDL", "BZÖ", "BIER", "CPÖ", "GILT", "SLP"], [1789417, 1011868, 772666, 387124, 89169, 664055, 32736, 22168, 760, 4946, 260, 1767, 310], [71, 40, 31, 15, 0, 26, 0, 0, 0, 0, 0, 0, 0])
+(2017, ["SPÖ", "ÖVP", "FPÖ", "GRÜNE", "NEOS", "PILZ", "GILT", "FLÖ", "KPÖ", "WEIßE", "SLP", "EUAUS", "M", "CPÖ", "NBZ", "ODP"], [1361746, 1595526, 1316442, 192638, 268518, 223543, 48234, 8889, 39689, 9167, 713, 693, 221, 425, 2724, 761], [52, 62, 51, 0, 10, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
+(2013, ["SPÖ", "ÖVP", "FPÖ","BZÖ", "GRÜNE", "FRANK", "NEOS", "KPÖ", "PIRAT", "CPÖ", "WANDL", "M", "EUAUS", "SLP"], [1258605, 1125876, 962313, 165746, 582657, 268679, 243946, 48175, 36265, 6647, 3051, 490, 510, 947], [52, 47, 40, 0, 24, 11, 9, 0, 0, 0, 0, 0, 0, 0])
+(2008, ["SPÖ", "ÖVP", "GRÜNE", "FPÖ", "BZÖ", "FRITZ", "DC", "KPÖ", "LIF", "RETTÖ", "LINKE", "KLEMENTE", "LINKE", "STARK", "TRP"], [1430206, 1269656, 509936, 857029, 522933, 86194, 31080, 37362, 102249, 35718, 349, 347, 1789, 237, 2224], [57, 51, 20, 34, 21, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])  # LINKE = Die Linke und LINKE = Linke
+(2006, ["ÖVP", "SPÖ", "FPÖ", "GRÜNE", "BZÖ", "KPÖ", "MATIN", "NFÖ", "IVE", "STARK", "SAU", "SLP"], [1616493, 1663986, 519598, 520130, 193539, 47578, 131688, 10594, 592, 312, 1514, 2257], [66, 68, 21, 21, 7, 0, 0, 0, 0, 0, 0, 0])
+(2002, ["SPÖ", "FPÖ", "ÖVP", "GRÜNE", "KPÖ", "LIF", "DD", "CWG", "SLP"], [1792499, 491328, 2076833, 454980, 27568, 48083, 2439, 2009, 3906], [69, 18, 79, 17, 0, 0, 0, 0, 0])
+(1999, ["SPÖ", "ÖVP", "FPÖ", "LIF", "GRÜNE", "KPÖ", "DU", "NEIN", "CWG"], [1532448, 1243672, 1244087, 168612, 342260, 22016, 46943, 19286, 3030], [65, 52, 52, 0, 14, 0, 0, 0, 0])
+(1995, ["SPÖ", "ÖVP", "FPÖ", "GRÜNE", "LIF", "NEIN", "KPÖ", "ÖNP", "DBP"], [1843474, 1370510, 1060377, 233208, 267026, 53176, 13938, 1634, 830], [71, 52, 41, 9, 10, 0, 0, 0, 0])
+(1994, ["SPÖ", "ÖVP", "FPÖ", "GRÜNE", "LIF", "VGÖ", "KPÖ", "BGÖ", "NEIN", "CWG", "ÖNP", "FG", "DBP"],  [1617804, 1281846, 1042332, 338538, 276580, 5776, 11919, 2504, 41492, 9051, 4209, 482, 581], [65, 52, 42, 13, 11, 0, 0, 0, 0, 0, 0, 0, 0])