Add comments

2 files changed, 17 insertions, 0 deletions

diff --git a/sumofsquares/constraints.py b/sumofsquares/constraints.py
index 3d681c5..b808bbb 100644
--- a/sumofsquares/constraints.py
+++ b/sumofsquares/constraints.py
@@ -69,6 +69,14 @@ class NonNegative(Constraint[E]):
     be written as a sum-of-squares, hence this constraint can also be
     understood as `expression` being SOS.
     """
+
+    # This was part of the docstring but is not implemented yet
+    # TODO: implement what is says below
+    #
+    # If the expression is a column vector, the interpretation is row-wise. In
+    # other words each row must be non-negative on the domain (or everywhere if
+    # not specified).
+
     expression: E 
     domain: BasicSemialgebraicSet[E] | None = None
 
@@ -88,4 +96,12 @@ class PositiveSemiDefinite(Constraint[E]):
 
 @dataclassabc(frozen=True)
 class ExponentialCone(Constraint[E]):
+    r"""
+    This constraint expects a 3d row vector :math:`(x, y, z)`, and imposes that
+    the point is inside of the exponential cone.
+
+    The expression may also be a :math:`n\times 2` matrix. In that case the
+    constraint is understood row-wise, or in other words, each row is taken as
+    a single point that must be inside of the exponential cone.
+    """
     expression: E
diff --git a/sumofsquares/problems.py b/sumofsquares/problems.py
index 6161641..3fed54f 100644
--- a/sumofsquares/problems.py
+++ b/sumofsquares/problems.py
@@ -152,6 +152,7 @@ class SOSProblem(Problem):
         # result may not be used, this is necessary to account for the case of
         # variables that are only present in the constraints, which the state
         # object may not contain yet.
+
         # TODO: Is there a more efficient way? There has to be a better way.
         for c in self.constraints:
             state, _  = c.expression.apply(state)