New math operations

chatterbot/logic/mathematical_evaluation.py

@@ -5,6 +5,7 @@
 import os
 import json
 import decimal
+import numpy
 
 
 class MathematicalEvaluation(LogicAdapter):
@@ -21,6 +22,7 @@ class MathematicalEvaluation(LogicAdapter):
     4) Simplify the equation
     5) Solve the equation & return result
     """
+    functions = ['log', 'sqrt']
 
     def __init__(self, **kwargs):
         super(MathematicalEvaluation, self).__init__(**kwargs)
@@ -72,7 +74,7 @@ def process(self, statement):
 
         # Returning important information
         try:
-            expression += "= " + str(eval(expression))
+            expression += "= " + str(eval(expression, {f: getattr(numpy, f) for f in self.functions}))
 
             # return a confidence of 1 if the expression could be evaluated
             return 1, Statement(expression)
@@ -84,23 +86,16 @@ def simplify_chunks(self, input_text):
         Separates the incoming text.
         """
         string = ''
+        chunks = re.split(r"([\w\.-]+|[\(\)\*\+])", input_text)
+        chunks = [chunk.strip() for chunk in chunks]
+        chunks = [chunk for chunk in chunks if chunk != '']
 
-        for chunk in input_text.split():
-
-            is_chunk_integer = self.is_integer(chunk)
-
-            if is_chunk_integer is False:
-                is_chunk_float = self.is_float(chunk)
-
-                if is_chunk_float is False:
-                    is_chunk_operator = self.is_operator(chunk)
-
-                    if is_chunk_operator is not False:
-                        string += str(is_chunk_operator) + ' '
-                else:
-                    string += str(is_chunk_float) + ' '
-            else:
-                string += str(is_chunk_integer) + ' '
+        for chunk in chunks:
+            for checker in ['is_integer', 'is_float', 'is_operator', 'is_constant', 'is_function']:
+                result = getattr(self, checker)(chunk)
+                if result is not False:
+                    string += str(result) + ' '
+                    break
 
         return string
 
@@ -126,6 +121,27 @@ def is_integer(self, string):
         except:
             return False
 
+    def is_constant(self, string):
+        """
+        If the string is a mathematical constant, returns
+        said constant. Otherwise, it returns False.
+        """
+        constants = {
+            "pi": 3.141693,
+            "e": 2.718281
+        }
+        return constants.get(string, False)
+
+    def is_function(self, string):
+        """
+        If the string is an availbale mathematical function, returns
+        said function. Otherwise, it returns False.
+        """
+        if string in self.functions:
+            return string
+        else:
+            return False
+
     def is_operator(self, string):
         """
         If the string is an operator, returns

tests/logic_adapter_tests/test_mathematical_evaluation.py

@@ -127,3 +127,14 @@ def test_negative_decimal_multiplication(self):
         statement = Statement('What is -100.5 * 20?')
         confidence, response = self.adapter.process(statement)
         self.assertEqual(response.text, '( -100.5 * 20 ) = -2010.0')
+
+    def test_constants(self):
+        statement = Statement('What is pi plus e ?')
+        confidence, response = self.adapter.process(statement)
+        self.assertEqual(response.text, '3.141693 + 2.718281 = 5.859974')
+
+    def test_math_functions(self):
+        statement = Statement('What is log ( 5 + 6 ) * sqrt ( 12 ) ?')
+        confidence, response = self.adapter.process(statement)
+        self.assertEqual(response.text, 'log ( ( 5 + ( 6 ) * sqrt ( ( 12 ) ) ) ) = 3.24977779033')
+