Add __str__ method to InternalSOSProblem for debugging

1 files changed, 11 insertions, 0 deletions

diff --git a/sumofsquares/problems.py b/sumofsquares/problems.py
index cd182df..fb25fd9 100644
--- a/sumofsquares/problems.py
+++ b/sumofsquares/problems.py
@@ -309,6 +309,17 @@ class InternalSOSProblem(Problem):
     polynomial_symbols: Sequence[Symbol]
     solver: Solver
 
+    def __str__(self):
+        n = len(self.constraints)
+        s = f"Internal SumOfSquares Problem ({self.__class__.__qualname__}):\n\n" \
+            f"minimize  {self.cost}\n" \
+            f"subject to ({n} constraint{'s' if n > 1 else ''})\n"
+
+        for i, c in enumerate(self.constraints):
+            s += f"nr. {i}:\n{str(c)}\n\n"
+
+        return s
+
     def to_conic_problem(self, state: ExpressionState, verbose: bool = False) -> ConicProblem:
         """
         Convert the SOS problem into a Conic program.