feat: compute z-scores at /z-score

app_ratings/models.py

@@ -1,9 +1,12 @@
+import itertools
 from django.db import models
 from django.core.validators import MaxValueValidator, MinValueValidator
 from django.contrib.auth.models import User
 from django.db.models import Avg
 from django_countries.fields import CountryField
 from django.utils.functional import cached_property
+import numpy as np
+import scipy.stats as stats
 
 class Country(models.Model):
     running_order = models.IntegerField()
@@ -27,6 +30,21 @@ def average_score(self):
         else:
             avg = str(round(avg, 2))
         return avg
+
+    @cached_property
+    def z_score(self):
+        z_scores_for_country = []
+        for user in User.objects.all():
+            country_ids = list(Rating.objects.filter(voter=user.id).values_list("country__id", flat=True))
+            user_ratings = np.array(
+                list(
+                    itertools.chain(*Rating.objects.filter(voter=user.id).values_list("score")))
+            )
+            z_scores = stats.zscore(user_ratings)
+            for i in range(0, len(country_ids)):
+                if country_ids[i] == self.id:
+                    z_scores_for_country.append(round(z_scores[i], 3))
+        return round(sum(z_scores_for_country) / len(z_scores_for_country), 3)
 
 class Rating(models.Model):
     score = models.IntegerField(

app_ratings/urls.py

@@ -1,9 +1,10 @@
 from django.urls import path
-from .views import CreateRating, EditRating, MyRatings, AllRatings
+from .views import CreateRating, EditRating, MyRatings, AllRatings, ZScoreRatings
 
 urlpatterns = [
     path('rate/', CreateRating.as_view(), name='rate'),
     path('update_rate/<int:pk>/', EditRating.as_view(), name='edit_rating'),
     path('', MyRatings.as_view(), name='my_ratings'),
     path('results/', AllRatings.as_view(), name='all_ratings'),
+    path('z-score/', ZScoreRatings.as_view(), name='z_score_ratings'),
 ]

app_ratings/views.py

@@ -109,8 +109,7 @@ def get_all_ratings(self):
         table_data = []
 
         for country in countries:
-            table_data.append({"Running Order": f"{country.running_order}", "Country": f"{country.country.name}",
-                               "Average Score": country.average_score})
+            table_data.append(self.get_table_data_row(country))
             country_ratings = ratings.filter(country=country)
             for user in users:
                 if country_ratings.filter(voter=user).exists():
@@ -120,6 +119,15 @@ def get_all_ratings(self):
                     table_data[-1][user.username] = "-"
 
         return table_data
+
+    def get_table_data_row(self, country: Country):
+        return {"Running Order": f"{country.running_order}", "Country": f"{country.country.name}",
+                               "Average Score": country.average_score}
 
     def get_users(self):
         return User.objects.all()
+
+class ZScoreRatings(AllRatings):
+    def get_table_data_row(self, country: Country):
+        return {"Running Order": f"{country.running_order}", "Country": f"{country.country.name}",
+                               "Z-Score": country.z_score}

requirements.txt

@@ -5,4 +5,6 @@ django-crispy-forms==2.0
 django-import-export==3.2.0
 crispy-bootstrap5==0.7
 django-storages[azure]
-mysqlclient==2.1.1
+mysqlclient==2.1.1
+numpy==1.24.3
+scipy==1.10.1