Refactored weight code to split the work over Search, ResultURL, and Click models...

[philo.git] / contrib / sobol / models.py

diff --git a/contrib/sobol/models.py b/contrib/sobol/models.py
index cd9b698..7e11882 100644 (file)
--- a/contrib/sobol/models.py
+++ b/contrib/sobol/models.py
@@ -1,8 +1,10 @@
 from django.conf.urls.defaults import patterns, url
 from django.contrib import messages
 from django.conf.urls.defaults import patterns, url
 from django.contrib import messages

+from django.core.exceptions import ValidationError

 from django.db import models
 from django.http import HttpResponseRedirect, Http404
 from django.utils import simplejson as json
 from django.db import models
 from django.http import HttpResponseRedirect, Http404
 from django.utils import simplejson as json

+from django.utils.datastructures import SortedDict

 from philo.contrib.sobol import registry
 from philo.contrib.sobol.forms import SearchForm
 from philo.contrib.sobol.utils import HASH_REDIRECT_GET_KEY, URL_REDIRECT_GET_KEY, SEARCH_ARG_GET_KEY, check_redirect_hash
 from philo.contrib.sobol import registry
 from philo.contrib.sobol.forms import SearchForm
 from philo.contrib.sobol.utils import HASH_REDIRECT_GET_KEY, URL_REDIRECT_GET_KEY, SEARCH_ARG_GET_KEY, check_redirect_hash


@@ -23,51 +25,50 @@ class Search(models.Model):
        def __unicode__(self):
                return self.string
        
        def __unicode__(self):
                return self.string
        

-       def get_favored_results(self, error=5):
-               """Calculate the set of most-favored results. A higher error
-               will cause this method to be more reticent about adding new
-               items."""
-               results = self.result_urls.values_list('pk', 'url',)
-               
-               result_dict = {}
-               for pk, url in results:
-                       result_dict[pk] = {'url': url, 'value': 0}
-               
-               clicks = Click.objects.filter(result__pk__in=result_dict.keys()).values_list('result__pk', 'datetime')
-               
-               now = datetime.datetime.now()
-               
-               def datetime_value(dt):
-                       days = (now - dt).days
-                       if days < 0:
-                               raise ValueError("Click dates must be in the past.")
-                       if days == 0:
-                               value = 1.0
-                       else:
-                               value = 1.0/days**2
-                       return value
-               
-               for pk, dt in clicks:
-                       value = datetime_value(dt)
-                       result_dict[pk]['value'] += value
-               
-               #TODO: is there a reasonable minimum value for consideration?
-               subsets = {}
-               for d in result_dict.values():
-                       subsets.setdefault(d['value'], []).append(d)
-               
-               # Now calculate the result set.
-               results = []
+       def get_weighted_results(self, threshhold=None):
+               "Returns this search's results ordered by decreasing weight."
+               if not hasattr(self, '_weighted_results'):
+                       result_qs = self.result_urls.all()
+                       
+                       if threshhold is not None:
+                               result_qs = result_qs.filter(counts__datetime__gte=threshhold)
+                       
+                       results = [result for result in result_qs]
+                       
+                       results.sort(cmp=lambda x,y: cmp(y.weight, x.weight))
+                       
+                       self._weighted_results = results

                
                

-               def cost(value):
-                       return error*sum([(value - item['value'])**2 for item in results])
+               return self._weighted_results
+       
+       def get_favored_results(self, error=5, threshhold=None):
+               """
+               Calculate the set of most-favored results. A higher error
+               will cause this method to be more reticent about adding new
+               items.

                
                

-               for value, subset in sorted(subsets.items(), cmp=lambda x,y: cmp(y[0], x[0])):
-                       if value > cost(value):
-                               results += subset
-                       else:
-                               break
-               return results
+               The thought is to see whether there are any results which
+               vastly outstrip the other options. As such, evenly-weighted
+               results should be grouped together and either added or
+               excluded as a group.
+               """
+               if not hasattr(self, '_favored_results'):
+                       results = self.get_weighted_results(threshhold)
+                       
+                       grouped_results = SortedDict()
+                       
+                       for result in results:
+                               grouped_results.setdefault(result.weight, []).append(result)
+                       
+                       self._favored_results = []
+                       
+                       for value, subresults in grouped_results.items():
+                               cost = error * sum([(value - result.weight)**2 for result in results])
+                               if value > cost:
+                                       self._favored_results += subresults
+                               else:
+                                       break
+               return self._favored_results

        
        class Meta:
                ordering = ['string']
        
        class Meta:
                ordering = ['string']


@@ -81,6 +82,18 @@ class ResultURL(models.Model):
        def __unicode__(self):
                return self.url
        
        def __unicode__(self):
                return self.url
        

+       def get_weight(self, threshhold=None):
+               if not hasattr(self, '_weight'):
+                       clicks = self.clicks.all()
+                       
+                       if threshhold is not None:
+                               clicks = clicks.filter(datetime__gte=threshhold)
+                       
+                       self._weight = sum([click.weight for click in clicks])
+               
+               return self._weight
+       weight = property(get_weight)
+       

        class Meta:
                ordering = ['url']
 
        class Meta:
                ordering = ['url']
 


@@ -92,6 +105,23 @@ class Click(models.Model):
        def __unicode__(self):
                return self.datetime.strftime('%B %d, %Y %H:%M:%S')
        
        def __unicode__(self):
                return self.datetime.strftime('%B %d, %Y %H:%M:%S')
        

+       def get_weight(self, default=1, weighted=lambda value, days: value/days**2):
+               if not hasattr(self, '_weight'):
+                       days = (datetime.datetime.now() - self.datetime).days
+                       if days < 0:
+                               raise ValueError("Click dates must be in the past.")
+                       default = float(default)
+                       if days == 0:
+                               self._weight = float(default)
+                       else:
+                               self._weight = weighted(default, days)
+               return self._weight
+       weight = property(get_weight)
+       
+       def clean(self):
+               if self.datetime > datetime.datetime.now():
+                       raise ValidationError("Click dates must be in the past.")
+       

        class Meta:
                ordering = ['datetime']
                get_latest_by = 'datetime'
        class Meta:
                ordering = ['datetime']
                get_latest_by = 'datetime'


@@ -103,6 +133,8 @@ class SearchView(MultiView):
        enable_ajax_api = models.BooleanField("Enable AJAX API", default=True)
        placeholder_text = models.CharField(max_length=75, default="Search")
        
        enable_ajax_api = models.BooleanField("Enable AJAX API", default=True)
        placeholder_text = models.CharField(max_length=75, default="Search")
        

+       search_form = SearchForm
+       

        def __unicode__(self):
                return u"%s (%s)" % (self.placeholder_text, u", ".join([display for slug, display in registry.iterchoices()]))
        
        def __unicode__(self):
                return u"%s (%s)" % (self.placeholder_text, u", ".join([display for slug, display in registry.iterchoices()]))
        


@@ -130,7 +162,7 @@ class SearchView(MultiView):
                context.update(extra_context or {})
                
                if SEARCH_ARG_GET_KEY in request.GET:
                context.update(extra_context or {})
                
                if SEARCH_ARG_GET_KEY in request.GET:

-                       form = SearchForm(request.GET)
+                       form = self.search_form(request.GET)

                        
                        if form.is_valid():
                                search_string = request.GET[SEARCH_ARG_GET_KEY].lower()
                        
                        if form.is_valid():
                                search_string = request.GET[SEARCH_ARG_GET_KEY].lower()