Fixed problems with psychometrics

- Update key comparisons for Opaque Keys
- Search for 'problem_check' instead of 'save_problem_check' when
  filtering TrackingLogs.

(cherry picked from commit efa44003)

lms/djangoapps/psychometrics/management/commands/init_psychometrics.py

@@ -52,9 +52,9 @@ class Command(BaseCommand):
 
                 # get attempt times from tracking log
                 uname = sm.student.username
-                tset = TrackingLog.objects.using(db).filter(username=uname, event_type__contains='save_problem_check')
+                tset = TrackingLog.objects.using(db).filter(username=uname, event_type__contains='problem_check')
                 tset = tset.filter(event_source='server')
-                tset = tset.filter(event__contains="'%s'" % url)
+                tset = tset.filter(event__contains="'%s'" % usage_key)
                 checktimes = [x.dtcreated for x in tset]
                 pmd.checktimes = checktimes
                 if not len(checktimes) == pmd.attempts:

lms/djangoapps/psychometrics/psychoanalyze.py

@@ -10,6 +10,7 @@ import logging
 import json
 import math
 import numpy as np
+from opaque_keys.edx.locator import BlockUsageLocator
 from scipy.optimize import curve_fit
 
 from django.conf import settings
@@ -129,7 +130,14 @@ def problems_with_psychometric_data(course_id):
     '''
     pmdset = PsychometricData.objects.using(db).filter(studentmodule__course_id=course_id)
     plist = [p['studentmodule__module_state_key'] for p in pmdset.values('studentmodule__module_state_key').distinct()]
-    problems = dict((p, pmdset.filter(studentmodule__module_state_key=p).count()) for p in plist)
+    problems = dict(
+        (
+            p,
+            pmdset.filter(
+                studentmodule__module_state_key=BlockUsageLocator.from_string(p)
+            ).count()
+        ) for p in plist
+    )
 
     return problems
 
@@ -138,7 +146,9 @@ def problems_with_psychometric_data(course_id):
 
 def generate_plots_for_problem(problem):
 
-    pmdset = PsychometricData.objects.using(db).filter(studentmodule__module_state_key=problem)
+    pmdset = PsychometricData.objects.using(db).filter(
+        studentmodule__module_state_key=BlockUsageLocator.from_string(problem)
+    )
     nstudents = pmdset.count()
     msg = ""
     plots = []