split example visualizaiton pipeline

src/orisys/hhd/solvers/masked_sparse.py

@@ -17,7 +17,10 @@ class MaskedSparseSolver:
         if rhs.size == 0:
             return numpy.zeros_like(f, dtype=numpy.float32)
 
-        sol_active = domain.factor(rhs)  # (N,) reduced-system potential
+        # MaskedDomain builds a positive diagonal / negative off-diagonal stencil
+        # for (-Laplace). Negate the direct solve result so the masked sparse path
+        # matches the FFT solver convention used elsewhere: Laplace(u) = rhs.
+        sol_active = -domain.factor(rhs)  # (N,) reduced-system potential
         return domain.scatter(sol_active, f)
 
     def solve_pair(self, f0, f1, domain: MaskedDomain):
@@ -28,9 +31,9 @@ class MaskedSparseSolver:
             return empty, empty.copy()
 
         try:
-            sol_pair = domain.factor(rhs_pair)  # (N, 2) reduced-system potentials
+            sol_pair = -domain.factor(rhs_pair)  # (N, 2) reduced-system potentials
         except Exception:
-            sol_pair = numpy.column_stack(
+            sol_pair = -numpy.column_stack(
                 [domain.factor(rhs_pair[:, 0]), domain.factor(rhs_pair[:, 1])]
             )
         return domain.scatter_pair(sol_pair, f0)