Make PosDefMatrix Op output type boolean

Author: juanitorduz

pymc/distributions/multivariate.py

@@ -849,9 +849,9 @@ def dist(cls, *args, **kwargs):
 def posdef(AA):
     try:
         linalg.cholesky(AA)
-        return 1
+        return True
     except linalg.LinAlgError:
-        return 0
+        return False
 
 
 class PosDefMatrix(Op):
@@ -868,15 +868,15 @@ class PosDefMatrix(Op):
     def make_node(self, x):
         x = pt.as_tensor_variable(x)
         assert x.ndim == 2
-        o = TensorType(dtype="int8", shape=[])()
+        o = TensorType(dtype="bool", shape=[])()
         return Apply(self, [x], [o])
 
     # Python implementation:
     def perform(self, node, inputs, outputs):
         (x,) = inputs
         (z,) = outputs
         try:
-            z[0] = np.array(posdef(x), dtype="int8")
+            z[0] = np.array(posdef(x), dtype="bool")
         except Exception:
             pm._log.exception("Failed to check if %s positive definite", x)
             raise

tests/distributions/test_multivariate.py

@@ -2130,10 +2130,10 @@ def test_car_rng_fn(sparse):
 @pytest.mark.parametrize(
     "matrix, result",
     [
-        ([[1.0, 0], [0, 1]], 1),
-        ([[1.0, 2], [2, 1]], 0),
-        ([[1.0, 1], [1, 1]], 0),
-        ([[1, 0.99, 1], [0.99, 1, 0.999], [1, 0.999, 1]], 0),
+        ([[1.0, 0], [0, 1]], True),
+        ([[1.0, 2], [2, 1]], False),
+        ([[1.0, 1], [1, 1]], False),
+        ([[1, 0.99, 1], [0.99, 1, 0.999], [1, 0.999, 1]], False),
     ],
 )
 def test_posdef_symmetric(matrix, result):