X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Fcone%2Fcone.py;h=8790c30673a25af96c29bf22ff9e84458516da09;hb=744bc420b47449500f0365e093467ffd268aeda2;hp=43ec8f7f18f031bea3e159f2f434b72b4d05909b;hpb=75a1cc8b3affcc1ffcf4fa68572ede75873b9380;p=sage.d.git

diff --git a/mjo/cone/cone.py b/mjo/cone/cone.py
index 43ec8f7..8790c30 100644
--- a/mjo/cone/cone.py
+++ b/mjo/cone/cone.py
@@ -359,20 +359,8 @@ def positive_operator_gens(K):
         sage: actual == 3
         True
 
-    The cone of positive operators is solid when the original cone is proper::
-
-        sage: set_random_seed()
-        sage: K = random_cone(max_ambient_dim=5,
-        ....:                 strictly_convex=True,
-        ....:                 solid=True)
-        sage: pi_of_K = positive_operator_gens(K)
-        sage: L = ToricLattice(K.lattice_dim()**2)
-        sage: pi_cone = Cone([p.list() for p in pi_of_K], lattice=L)
-        sage: pi_cone.is_solid()
-        True
-
-    The lineality of the cone of positive operators is given by the
-    corollary in my paper::
+    The lineality of the cone of positive operators follows from the
+    description of its generators::
 
         sage: set_random_seed()
         sage: K = random_cone(max_ambient_dim=5)
@@ -384,8 +372,33 @@ def positive_operator_gens(K):
         sage: actual == expected
         True
 
-    The cone ``K`` is proper if and only if the cone of positive
-    operators on ``K`` is proper::
+    The trivial cone, full space, and half-plane all give rise to the
+    expected linealities::
+
+        sage: n = ZZ.random_element().abs()
+        sage: K = Cone([[0] * n], ToricLattice(n))
+        sage: K.is_trivial()
+        True
+        sage: L = ToricLattice(n^2)
+        sage: pi_of_K = positive_operator_gens(K)
+        sage: actual = Cone([p.list() for p in pi_of_K], lattice=L).lineality()
+        sage: actual == n^2
+        True
+        sage: K = K.dual()
+        sage: K.is_full_space()
+        True
+        sage: pi_of_K = positive_operator_gens(K)
+        sage: actual = Cone([p.list() for p in pi_of_K], lattice=L).lineality()
+        sage: actual == n^2
+        True
+        sage: K = Cone([(1,0),(0,1),(0,-1)])
+        sage: pi_of_K = positive_operator_gens(K)
+        sage: actual = Cone([p.list() for p in pi_of_K]).lineality()
+        sage: actual == 2
+        True
+
+    A cone is proper if and only if its cone of positive operators
+    is proper::
 
         sage: set_random_seed()
         sage: K = random_cone(max_ambient_dim=5)
@@ -408,8 +421,9 @@ def positive_operator_gens(K):
     vectors = [ W(tp.list()) for tp in tensor_products ]
 
     # Create the *dual* cone of the positive operators, expressed as
-    # long vectors. WARNING: takes forever unless we pass check=False
-    # to Cone().
+    # long vectors. WARNING: check=True is necessary even though it
+    # makes Cone() take forever. For an example take
+    # K = Cone([(1,0,0),(0,0,1),(0,0,-1)]).
     pi_dual = Cone(vectors, ToricLattice(W.dimension()))
 
     # Now compute the desired cone from its dual...
@@ -525,8 +539,9 @@ def Z_transformation_gens(K):
     vectors = [ W(m.list()) for m in tensor_products ]
 
     # Create the *dual* cone of the cross-positive operators,
-    # expressed as long vectors. WARNING: takes forever unless we pass
-    # check=False to Cone().
+    # expressed as long vectors. WARNING: check=True is necessary
+    # even though it makes Cone() take forever. For an example take
+    # K = Cone([(1,0,0),(0,0,1),(0,0,-1)]).
     Sigma_dual = Cone(vectors, lattice=ToricLattice(W.dimension()))
 
     # Now compute the desired cone from its dual...