Merge pull request #9 from MITx/pmitros/complex-numbers-fix

Complex numbers now work in problems

.gitignore

@@ -10,3 +10,4 @@ db.newaskbot
 db.oldaskbot
 flushdb.sh
 build
+\#*\#

djangoapps/courseware/capa/calc.py

@@ -5,6 +5,7 @@ import operator
 import re
 
 import numpy
+import numbers
 import scipy.constants
 
 from pyparsing import Word, alphas, nums, oneOf, Literal
@@ -121,7 +122,7 @@ def evaluator(variables, functions, string, cs=False):
     def number_parse_action(x): # [ '7' ] ->  [ 7 ]
         return [super_float("".join(x))]
     def exp_parse_action(x): # [ 2 ^ 3 ^ 2 ] -> 512
-        x = [e for e in x if type(e) in [float, numpy.float64, numpy.complex]] # Ignore ^
+        x = [e for e in x if isinstance(e, numbers.Number)] # Ignore ^
         x.reverse()
         x=reduce(lambda a,b:b**a, x)
         return x
@@ -130,7 +131,7 @@ def evaluator(variables, functions, string, cs=False):
             return x[0]
         if 0 in x:
             return float('nan')
-        x = [1./e for e in x if type(e) == float] # Ignore ^
+        x = [1./e for e in x if isinstance(e, numbers.Number)] # Ignore ||
         return 1./sum(x)
     def sum_parse_action(x): # [ 1 + 2 - 3 ] -> 0
         total = 0.0
@@ -217,4 +218,7 @@ if __name__=='__main__':
     print evaluator({},{}, "-(7+5)")
     print evaluator({},{}, "-0.33")
     print evaluator({},{}, "-.33")
+    print evaluator({},{}, "5+1*j")
+    print evaluator({},{}, "j||1")
+    print evaluator({},{}, "e^(j*pi)")
     print evaluator({},{}, "5+7 QWSEKO")

djangoapps/courseware/capa/responsetypes.py

@@ -1,5 +1,6 @@
 import json
 import math
+import numbers
 import numpy
 import random
 import scipy
@@ -37,7 +38,7 @@ class numericalresponse(object):
     def __init__(self, xml, context):
         self.xml = xml
         self.correct_answer = contextualize_text(xml.get('answer'), context)
-        self.correct_answer = float(self.correct_answer)
+        self.correct_answer = complex(self.correct_answer)
         self.tolerance_xml = xml.xpath('//*[@id=$id]//responseparam[@type="tolerance"]/@default',
                                    id=xml.get('id'))[0]
         self.tolerance = contextualize_text(self.tolerance_xml, context)
@@ -49,7 +50,10 @@ class numericalresponse(object):
         student_answer = student_answers[self.answer_id]
         try:
             correct = compare_with_tolerance (evaluator(dict(),dict(),student_answer), self.correct_answer, self.tolerance)
-        except:
+        # We should catch this explicitly. 
+        # I think this is just pyparsing.ParseException, calc.UndefinedVariable:
+        # But we'd need to confirm
+        except: 
             raise StudentInputError('Invalid input -- please use a number only')
 
         if correct:
@@ -141,7 +145,7 @@ class formularesponse(object):
             except:
                 #traceback.print_exc()
                 raise StudentInputError("Error in formula")
-            if math.isnan(student_result) or math.isinf(student_result):
+            if numpy.isnan(student_result) or numpy.isinf(student_result):
                 return {self.answer_id:"incorrect"}
             if not compare_with_tolerance(student_result, instructor_result, self.tolerance):
                 return {self.answer_id:"incorrect"}
@@ -153,9 +157,9 @@ class formularesponse(object):
         keys and all non-numeric values stripped out. All values also
         converted to float. Used so we can safely use Python contexts.
         ''' 
-        d=dict([(k, float(d[k])) for k in d if type(k)==str and \
+        d=dict([(k, numpy.complex(d[k])) for k in d if type(k)==str and \
                     k.isalnum() and \
-                    (type(d[k]) == float or type(d[k]) == int) ])
+                    isinstance(d[k], numbers.Number)])
         return d
 
     def get_answers(self):

djangoapps/courseware/tests.py

@@ -20,7 +20,7 @@ class ModelsTest(unittest.TestCase):
         variables={'R1':2.0, 'R3':4.0}
         functions={'sin':numpy.sin, 'cos':numpy.cos}
 
-        self.assertEqual(calc.evaluator(variables, functions, "10000||sin(7+5)-6k"), 4000.0)
+        self.assertTrue(abs(calc.evaluator(variables, functions, "10000||sin(7+5)+0.5356"))<0.01)
         self.assertEqual(calc.evaluator({'R1': 2.0, 'R3':4.0}, {}, "13"), 13)
         self.assertEqual(calc.evaluator(variables, functions, "13"), 13)
         self.assertEqual(calc.evaluator({'a': 2.2997471478310274, 'k': 9, 'm': 8, 'x': 0.66009498411213041}, {}, "5"), 5)
@@ -30,6 +30,8 @@ class ModelsTest(unittest.TestCase):
         self.assertEqual(calc.evaluator(variables, functions, "R1*R3"), 8.0)
         self.assertTrue(abs(calc.evaluator(variables, functions, "sin(e)-0.41"))<0.01)
         self.assertTrue(abs(calc.evaluator(variables, functions, "k*T/q-0.025"))<0.001)
+        self.assertTrue(abs(calc.evaluator(variables, functions, "e^(j*pi)")+1)<0.00001)
+        self.assertTrue(abs(calc.evaluator(variables, functions, "j||1")-0.5-0.5j)<0.00001)
         exception_happened = False
         try: 
             calc.evaluator({},{}, "5+7 QWSEKO")