Revert "added is_pwl() and is_qp()"

This reverts commit e10e836.

cvxpy/atoms/affine/affine_atom.py

@@ -59,9 +59,6 @@ def is_decr(self, idx):
     def is_quadratic(self):
         return all([arg.is_quadratic() for arg in self.args])
 
-    def is_pwl(self):
-        return all([arg.is_pwl() for arg in self.args])        
-
     def _grad(self, values):
         """Gives the (sub/super)gradient of the atom w.r.t. each argument.
 

cvxpy/atoms/elementwise/abs.py

@@ -59,11 +59,6 @@ def is_decr(self, idx):
         """
         return self.args[idx].is_negative()
 
-    def is_pwl(self):
-        """Is the atom piecewise linear?
-        """
-        return self.args[0].is_pwl()
-
     def _grad(self, values):
         """Gives the (sub/super)gradient of the atom w.r.t. each argument.
 

cvxpy/atoms/elementwise/max_elemwise.py

@@ -73,11 +73,6 @@ def is_decr(self, idx):
         """
         return False
 
-    def is_pwl(self):
-        """Is the atom piecewise linear?
-        """
-        return all ([arg.is_pwl() for arg in self.args])
-
     def _grad(self, values):
         """Gives the (sub/super)gradient of the atom w.r.t. each argument.
 

cvxpy/atoms/max_entries.py

@@ -93,11 +93,6 @@ def is_decr(self, idx):
         """
         return False
 
-    def is_pwl(self):
-        """Is the atom piecewise linear?
-        """
-        return self.args[0].is_pwl()
-
     @staticmethod
     def graph_implementation(arg_objs, size, data=None):
         """Reduces the atom to an affine expression and list of constraints.

cvxpy/atoms/pnorm.py

@@ -177,11 +177,6 @@ def is_decr(self, idx):
         """
         return self.p >= 1 and self.args[0].is_negative()
 
-    def is_pwl(self):
-        """Is the atom piecewise linear?
-        """
-        return (self.p == 1 or self.p == np.inf) and self.args[0].is_pwl()
-
     def get_data(self):
         return [self.p, self.axis]
 

cvxpy/expressions/expression.py

@@ -153,12 +153,6 @@ def is_quadratic(self):
         # Defaults to false
         return False
 
-    def is_pwl(self):
-        """Is the expression piecewise linear?
-        """
-        # Defaults to false
-        return False
-
     # Sign properties.
 
     @property

cvxpy/expressions/leaf.py

@@ -107,8 +107,3 @@ def is_quadratic(self):
         """Leaf nodes are always quadratic.
         """
         return True
-
-    def is_pwl(self):
-        """Leaf nodes are always piecewise linear.
-        """
-        return True

cvxpy/problems/problem.py

@@ -30,7 +30,6 @@
 # a circular import (cvxpy.transforms imports Problem). Hence we need to import
 # cvxpy here.
 import cvxpy
-import cvxpy.constraints.eq_constraint as eqc
 
 import multiprocess as multiprocessing
 import numpy as np
@@ -112,13 +111,6 @@ def is_dcp(self):
         """
         return all(exp.is_dcp() for exp in self.constraints + [self.objective])
 
-    def is_qp(self):
-        """Is problem a quadratic program?
-        """
-        return (self.is_dcp() and self.objective.args[0].is_quadratic() and
-            all([(isinstance(c, eqc.EqConstraint) or c._expr.is_pwl())
-                for c in self.constraints]))
-
     def canonicalize(self):
         """Computes the graph implementation of the problem.