Fix tb01pd wrapper for pre-padded arrays

jamestjsp · claude · jamestjsp · commit 2443fb98903e · 2026-02-03T15:41:11.000-06:00
Extract actual-sized submatrices using n,m,p params before calling slicot tb01pd, which infers dimensions from array shapes. Fixes jamestjsp/ctrlsys#12 Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
diff --git a/control/slicot_compat.py b/control/slicot_compat.py
@@ -811,9 +811,10 @@ def tb01pd(n, m, p, A, B, C, job='M', equil='S', tol=0.0, ldwork=None):
     """
     from slicot import tb01pd as _tb01pd
 
-    A_copy = np.asfortranarray(A.copy())
-    B_copy = np.asfortranarray(B.copy())
-    C_copy = np.asfortranarray(C.copy())
+    # Extract actual-sized arrays (caller may pass pre-padded arrays)
+    A_copy = np.asfortranarray(A[:n, :n].copy())
+    B_copy = np.asfortranarray(B[:n, :m].copy())
+    C_copy = np.asfortranarray(C[:p, :n].copy())
 
     if tol is None:
         tol = 0.0
diff --git a/control/tests/minreal_test.py b/control/tests/minreal_test.py
@@ -79,7 +79,8 @@ def testMinrealBrute(self):
                             # Find the closest zero
                             assert min(abs(z1 - z)) <= 1e-7
 
-        # Verify expected reductions occur (seed=5 yields 2 reducible systems)
+        # Make sure that the number of systems reduced is as expected
+        # (Need to update this number if you change the seed at top of file)
         assert nreductions == 2
 
     def testMinrealSS(self):
