Fix typo in doc/reference.rst

[linpy.git] / linpy / polyhedra.py

diff --git a/linpy/polyhedra.py b/linpy/polyhedra.py
index e9226f2..346ffff 100644 (file)
--- a/linpy/polyhedra.py
+++ b/linpy/polyhedra.py
@@ -23,7 +23,7 @@ from . import islhelper
 
 from .islhelper import mainctx, libisl
 from .geometry import GeometricObject, Point
-from .linexprs import Expression, Rational
+from .linexprs import LinExpr, Rational
 from .domains import Domain
 
 
@@ -35,7 +35,9 @@ __all__ = [
 
 
 class Polyhedron(Domain):
-
+    """
+    Polyhedron class allows users to build and inspect polyherons. Polyhedron inherits from Domain.
+    """
     __slots__ = (
         '_equalities',
         '_inequalities',
@@ -45,6 +47,10 @@ class Polyhedron(Domain):
     )
 
     def __new__(cls, equalities=None, inequalities=None):
+        """
+        Create and return a new Polyhedron from a string or list of equalities and inequalities.
+        """
+
         if isinstance(equalities, str):
             if inequalities is not None:
                 raise TypeError('too many arguments')
@@ -57,14 +63,14 @@ class Polyhedron(Domain):
             equalities = []
         else:
             for i, equality in enumerate(equalities):
-                if not isinstance(equality, Expression):
+                if not isinstance(equality, LinExpr):
                     raise TypeError('equalities must be linear expressions')
                 equalities[i] = equality.scaleint()
         if inequalities is None:
             inequalities = []
         else:
             for i, inequality in enumerate(inequalities):
-                if not isinstance(inequality, Expression):
+                if not isinstance(inequality, LinExpr):
                     raise TypeError('inequalities must be linear expressions')
                 inequalities[i] = inequality.scaleint()
         symbols = cls._xsymbols(equalities + inequalities)
@@ -74,21 +80,21 @@ class Polyhedron(Domain):
     @property
     def equalities(self):
         """
-        Return a list of the equalities in a set.
+        Return a list of the equalities in a polyhedron.
         """
         return self._equalities
 
     @property
     def inequalities(self):
         """
-        Return a list of the inequalities in a set.
+        Return a list of the inequalities in a polyhedron.
         """
         return self._inequalities
 
     @property
     def constraints(self):
         """
-        Return ta list of the constraints of a set.
+        Return the list of the constraints of a polyhedron.
         """
         return self._constraints
 
@@ -96,15 +102,15 @@ class Polyhedron(Domain):
     def polyhedra(self):
         return self,
 
-    def disjoint(self):
+    def make_disjoint(self):
         """
-        Return a set as disjoint.
+        Return a polyhedron as disjoint.
         """
         return self
 
     def isuniverse(self):
         """
-        Return true if a set is the Universe set.
+        Return true if a polyhedron is the Universe set.
         """
         islbset = self._toislbasicset(self.equalities, self.inequalities,
             self.symbols)
@@ -114,11 +120,14 @@ class Polyhedron(Domain):
 
     def aspolyhedron(self):
         """
-        Return polyhedral hull of a set.
+        Return the polyhedral hull of a polyhedron.
         """
         return self
 
     def __contains__(self, point):
+        """
+        Report whether a polyhedron constains an integer point
+        """
         if not isinstance(point, Point):
             raise TypeError('point must be a Point instance')
         if self.symbols != point.symbols:
@@ -182,7 +191,7 @@ class Polyhedron(Domain):
                 coefficient = islhelper.isl_val_to_int(coefficient)
                 if coefficient != 0:
                     coefficients[symbol] = coefficient
-            expression = Expression(coefficients, constant)
+            expression = LinExpr(coefficients, constant)
             if libisl.isl_constraint_is_equality(islconstraint):
                 equalities.append(expression)
             else:
@@ -233,6 +242,9 @@ class Polyhedron(Domain):
 
     @classmethod
     def fromstring(cls, string):
+        """
+        Create and return a Polyhedron from a string.
+        """
         domain = Domain.fromstring(string)
         if not isinstance(domain, Polyhedron):
             raise ValueError('non-polyhedral expression: {!r}'.format(string))
@@ -261,7 +273,7 @@ class Polyhedron(Domain):
     @classmethod
     def fromsympy(cls, expr):
         """
-        Convert a sympy object to an expression.
+        Convert a sympy object to a polyhedron.
         """
         domain = Domain.fromsympy(expr)
         if not isinstance(domain, Polyhedron):
@@ -270,7 +282,7 @@ class Polyhedron(Domain):
 
     def tosympy(self):
         """
-        Return an expression as a sympy object.
+        Return a polyhedron as a sympy object.
         """
         import sympy
         constraints = []
@@ -333,13 +345,13 @@ Universe = UniverseType()
 def _polymorphic(func):
     @functools.wraps(func)
     def wrapper(left, right):
-        if not isinstance(left, Expression):
+        if not isinstance(left, LinExpr):
             if isinstance(left, numbers.Rational):
                 left = Rational(left)
             else:
                 raise TypeError('left must be a a rational number '
                     'or a linear expression')
-        if not isinstance(right, Expression):
+        if not isinstance(right, LinExpr):
             if isinstance(right, numbers.Rational):
                 right = Rational(right)
             else:
@@ -351,41 +363,41 @@ def _polymorphic(func):
 @_polymorphic
 def Lt(left, right):
     """
-    Assert first set is less than the second set.
+    Returns a Polyhedron instance with a single constraint as left less than right.
     """
     return Polyhedron([], [right - left - 1])
 
 @_polymorphic
 def Le(left, right):
     """
-    Assert first set is less than or equal to the second set.
+    Returns a Polyhedron instance with a single constraint as left less than or equal to right.
     """
     return Polyhedron([], [right - left])
 
 @_polymorphic
 def Eq(left, right):
     """
-    Assert first set is equal to the second set.
+    Returns a Polyhedron instance with a single constraint as left equal to right.
     """
     return Polyhedron([left - right], [])
 
 @_polymorphic
 def Ne(left, right):
     """
-    Assert first set is not equal to the second set.
+    Returns a Polyhedron instance with a single constraint as left not equal to right.
     """
     return ~Eq(left, right)
 
 @_polymorphic
 def Gt(left, right):
     """
-    Assert first set is greater than the second set.
+    Returns a Polyhedron instance with a single constraint as left greater than right.
     """
     return Polyhedron([], [left - right - 1])
 
 @_polymorphic
 def Ge(left, right):
     """
-    Assert first set is greater than or equal to the second set.
+    Returns a Polyhedron instance with a single constraint as left greater than or equal to right.
     """
     return Polyhedron([], [left - right])