MathJAX and formula answers work

courseware/capa_problem.py

-# For calculator: 
-# http://pyparsing.wikispaces.com/file/view/fourFn.py
-
 import random, numpy, math, scipy, sys, StringIO, os, struct, json
 
 from xml.dom.minidom import parse, parseString
 
+from calc import evaluator
+
+def strip_dict(d):
+    ''' Takes a dict. Returns an identical dict, with all non-word keys stripped out. ''' 
+    d=dict([(k, float(d[k])) for k in d if type(k)==str and \
+                                           k.isalnum() and \
+                                           (type(d[k]) == float or type(d[k]) == int) ])
+    return d
+
 class LoncapaProblem():
     def get_state(self):
         ''' Stored per-user session data neeeded to: 
@@ -71,15 +77,15 @@ class LoncapaProblem():
 
         # Loop through the nodes of the problem, and 
         for e in dom.childNodes:
-            print e, ot
+#            print e, ot
             #
             if e.localName=='script':
-                print e.childNodes[0].data
+                #print e.childNodes[0].data
                 exec e.childNodes[0].data in g,self.context
             elif e.localName=='endouttext':
                 ot=False
             elif ot:
-                print e, "::", e.toxml()
+#                print e, "::", e.toxml()
                 e.writexml(buf)
             elif e.localName=='startouttext':
                 ot=True
@@ -93,7 +99,7 @@ class LoncapaProblem():
 
         self.text=buf.getvalue()
         self.text=self.contextualize_text(self.text)
-        print self.text
+#        print self.text
         self.filename=filename
 
     done=False
@@ -129,29 +135,34 @@ class LoncapaProblem():
            if id not in answers:
                correct_map[id]='incorrect' # Should always be there
            else:
-               correct_map[id]=self.grade_nr(self.questions[key],
-                                             self.answers[id])
+               #correct_map[id]=self.grade_nr(self.questions[key],
+               #                              self.answers[id])
+               grader=self.graders[self.questions[key]['type']]
+               print grader
+               correct_map[id]=grader(self, self.questions[key],
+                                      self.answers[id])
         self.correct_map=correct_map
         return correct_map
 
 
+
     ## Internal methods
-    def number(self,text):
-        ''' Convert a number to a float, understanding suffixes '''
-        try:
-            text.strip()
-            suffixes={'%':0.01,'k':1e3,'M':1e6,'G':1e9,'T':1e12,'P':1e15,
-                      'E':1e18,'Z':1e21,'Y':1e24,'c':1e-2,'m':1e-3,'u':1e-6,
-                      'n':1e-9,'p':1e-12,'f':1e-15,'a':1e-18,'z':1e-21,'y':1e-24}
-            if text[-1] in suffixes:
-                return float(text[:-1])*suffixes[text[-1]]
-            else:
-                return float(text)
-        except:
-            return 0 # TODO: Better error handling? 
+#    def number(self,text):
+#        ''' Convert a number to a float, understanding suffixes '''
+#        try:
+#            text.strip()
+#            suffixes={'%':0.01,'k':1e3,'M':1e6,'G':1e9,'T':1e12,'P':1e15,
+#                      'E':1e18,'Z':1e21,'Y':1e24,'c':1e-2,'m':1e-3,'u':1e-6,
+#                      'n':1e-9,'p':1e-12,'f':1e-15,'a':1e-18,'z':1e-21,'y':1e-24}
+#            if text[-1] in suffixes:
+#                return float(text[:-1])*suffixes[text[-1]]
+#            else:
+#                return float(text)
+#        except:
+#            return 0 # TODO: Better error handling? 
 
     def grade_nr(self, question, answer):
-        error = abs(self.number(answer) - question['answer'])
+        error = abs(evaluator({},{},answer) - question['answer'])
         allowed_error = abs(question['answer']*question['tolerance'])
         if error <= allowed_error:
             return 'correct'
@@ -165,13 +176,14 @@ class LoncapaProblem():
                 tolerance=e.getAttribute('default')
         self.lid+=1
         id=str(self.gid)+'_'+str(self.lid)
-        problem={"answer":self.number(self.contextualize_text(answer)),
+        problem={"answer":evaluator({},{},self.contextualize_text(answer)),
                  "type":"numericalresponse",
-                 "tolerance":self.number(self.contextualize_text(tolerance)),
+                 "tolerance":evaluator({},{},self.contextualize_text(tolerance)),
                  "id":id,
                  "lid":self.lid,
                  }
         self.questions[self.lid]=problem
+
         if id in self.answers:
             value=self.answers[id]
         else:
@@ -185,9 +197,64 @@ class LoncapaProblem():
         html='<input type="text" name="input_{id}" id="input_{id}" value="{value}"><span class="ui-icon ui-icon-{icon}" style="display:inline-block;" id="status_{id}"></span> '.format(id=id,value=value,icon=icon)
         return html
 
+    def grade_fr(self, question, answer):
+        correct = True
+        for i in range(question['samples_count']):
+            instructor_variables = strip_dict(dict(self.context))
+            student_variables = dict()
+            for var in question['sample_range']:
+                value = random.uniform(*question['sample_range'][var])
+                instructor_variables[str(var)] = value
+                student_variables[str(var)] = value
+            instructor_result = evaluator(instructor_variables,{},str(question['answer']))
+            student_result = evaluator(student_variables,{},str(answer))
+            if abs( student_result - instructor_result ) > question['tolerance']:
+                return "incorrect"
+ 
+        return "correct"
+
+    def handle_fr(self, element):
+        ## Extract description from element
+        samples=element.getAttribute('samples')
+        variables=samples.split('@')[0].split(',')
+        numsamples=int(samples.split('@')[1].split('#')[1])
+        sranges=zip(*map(lambda x:map(float, x.split(",")), samples.split('@')[1].split('#')[0].split(':')))
+        answer=element.getAttribute('answer')
+        for e in element.childNodes:
+            if e.nodeType==1 and e.getAttribute('type')=="tolerance":
+                tolerance=e.getAttribute('default')
+
+        # Store element
+        self.lid+=1
+        id=str(self.gid)+'_'+str(self.lid)
+        problem={"answer":self.contextualize_text(answer),
+                 "type":"formularesponse",
+                 "tolerance":evaluator({},{},self.contextualize_text(tolerance)),
+                 "sample_range":dict(zip(variables, sranges)),
+                 "samples_count": numsamples,
+                 "id":id,
+                 "lid":self.lid,
+                 }
+        self.questions[self.lid]=problem        
+
+        # Generate HTML
+        if id in self.answers:
+            value=self.answers[id]
+        else:
+            value=""
+        icon='bullet'
+        if id in self.correct_map and self.correct_map[id]=='correct':
+            icon='check'
+        if id in self.correct_map and self.correct_map[id]=='incorrect':
+            icon='close'
+
+        html='<input type="text" name="input_{id}" id="input_{id}" value="{value}"><span class="ui-icon ui-icon-{icon}" style="display:inline-block;" id="status_{id}"></span> '.format(id=id,value=value,icon=icon)
+        return html
 
-    graders={'numericalresponse':grade_nr}
-    handlers={'numericalresponse':handle_nr}
+    graders={'numericalresponse':grade_nr,
+             'formularesponse':grade_fr}
+    handlers={'numericalresponse':handle_nr,
+              'formularesponse':handle_fr}
 
     def contextualize_text(self, text):
         ''' Takes a string with variables. E.g. $a+$b.