Checks for variables with None value in NLP

idaes/core/util/model_diagnostics.py

@@ -100,6 +100,7 @@
     deactivated_objectives_set,
     variables_in_activated_constraints_set,
     variables_not_in_activated_constraints_set,
+    variables_with_none_value_in_activated_equalities_set,
     number_activated_greybox_equalities,
     number_deactivated_greybox_equalities,
     activated_greybox_block_set,
@@ -603,7 +604,7 @@ def display_variables_at_or_outside_bounds(self, stream=None):
                     tolerance=self.config.variable_bounds_violation_tolerance,
                 )
             ],
-            title=f"The following variable(s) have values at or outside their bounds "
+            title="The following variable(s) have values at or outside their bounds "
             f"(tol={self.config.variable_bounds_violation_tolerance:.1E}):",
             header="=",
             footer="=",
@@ -631,6 +632,54 @@ def display_variables_with_none_value(self, stream=None):
             footer="=",
         )
 
+    def display_variables_with_none_value_in_activated_constraints(self, stream=None):
+        """
+        Prints a list of variables with values of None that are present in the
+        mathematical program generated to solve the model. This list includes only
+        variables in active constraints that are reachable through active blocks.
+
+        Args:
+            stream: an I/O object to write the list to (default = stdout)
+
+        Returns:
+            None
+
+        """
+        if stream is None:
+            stream = sys.stdout
+
+        _write_report_section(
+            stream=stream,
+            lines_list=[
+                f"{v.name}"
+                for v in variables_with_none_value_in_activated_equalities_set(
+                    self._model
+                )
+            ],
+            title="The following variable(s) have a value of None:",
+            header="=",
+            footer="=",
+        )
+
+    def _verify_active_variables_initialized(self, stream=None):
+        """
+        Validate that all variables are initialized (i.e., have values set to
+        something other than None) before doing further numerical analysis.
+        Stream argument provided for forward compatibility (in case we want
+        to print a list or something).
+        """
+        n_uninit = len(
+            variables_with_none_value_in_activated_equalities_set(self._model)
+        )
+        if n_uninit > 0:
+            raise RuntimeError(
+                f"Found {n_uninit} variables with a value of None in the mathematical "
+                "program generated by the model. They must be initialized with non-None "
+                "values before numerical analysis can proceed. Run "
+                + self.display_variables_with_none_value_in_activated_constraints.__name__
+                + " to display a list of these variables."
+            )
+
     def display_variables_with_value_near_zero(self, stream=None):
         """
         Prints a list of variables with a value close to zero. The tolerance
@@ -942,6 +991,8 @@ def display_variables_with_extreme_jacobians(self, stream=None):
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -977,6 +1028,8 @@ def display_constraints_with_extreme_jacobians(self, stream=None):
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -1013,6 +1066,8 @@ def display_extreme_jacobian_entries(self, stream=None):
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -1046,6 +1101,8 @@ def display_near_parallel_constraints(self, stream=None):
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -1078,6 +1135,8 @@ def display_near_parallel_variables(self, stream=None):
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -1161,6 +1220,8 @@ def display_constraints_with_mismatched_terms(self, stream=None):
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -1194,6 +1255,8 @@ def display_constraints_with_canceling_terms(self, stream=None):
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -1232,6 +1295,8 @@ def display_problematic_constraint_terms(
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -1321,6 +1386,11 @@ def display_constraints_with_no_free_variables(self, stream=None):
             None
 
         """
+        # Although, in principle, this method doesn't require
+        # all variables to be initialized, its current
+        # implementation does.
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
 
@@ -1803,6 +1873,8 @@ def report_numerical_issues(self, stream=None):
             None
 
         """
+        self._verify_active_variables_initialized(stream=stream)
+
         if stream is None:
             stream = sys.stdout
         jac, nlp = get_jacobian(self._model, scaled=False)

idaes/core/util/model_statistics.py

@@ -1730,6 +1730,41 @@ def number_active_variables_in_deactivated_blocks(block):
     return len(active_variables_in_deactivated_blocks_set(block))
 
 
+def variables_with_none_value_in_activated_equalities_set(block):
+    """
+    Method to return a ComponentSet of all Var components which
+    have a value of None in the set of activated constraints.
+
+    Args:
+        block : model to be studied
+
+    Returns:
+        A ComponentSet including all Var components which
+        have a value of None in the set of activated constraints.
+    """
+    var_set = ComponentSet()
+    for v in variables_in_activated_equalities_set(block):
+        if v.value is None:
+            var_set.add(v)
+    return var_set
+
+
+def number_variables_with_none_value_in_activated_equalities(block):
+    """
+    Method to return the number of Var components which
+    have a value of None in the set of activated constraints.
+
+    Args:
+        block : model to be studied
+
+    Returns:
+        Number of Var components which
+        have a value of None in the set of activated constraints.
+    """
+
+    return len(variables_with_none_value_in_activated_equalities_set(block))
+
+
 # -------------------------------------------------------------------------
 # Reporting methods
 def report_statistics(block, ostream=None):

idaes/core/util/tests/test_model_diagnostics.py

@@ -185,6 +185,129 @@ def test_vars_near_zero(model):
         assert i is model.v1
 
 
+class TestVariablesWithNoneValue:
+    def err_msg(self, j):
+        return (
+            f"Found {j} variables with a value of None in the mathematical "
+            "program generated by the model. They must be initialized with non-None "
+            "values before numerical analysis can proceed. Run "
+            + DiagnosticsToolbox.display_variables_with_none_value_in_activated_constraints.__name__
+            + " to display a list of these variables."
+        )
+
+    @pytest.fixture(scope="function")
+    def model(self):
+        m = ConcreteModel()
+        m.u = Var()
+        m.w = Var(initialize=1)
+        m.x = Var(initialize=1)
+        m.y = Var(range(3), initialize=[1, None, 2])
+        m.z = Var()
+
+        m.con_w = Constraint(expr=m.w == 0)
+        m.con_x = Constraint(expr=m.x == 1)
+
+        def rule_con_y(b, i):
+            return b.y[i] == 3
+
+        m.con_y = Constraint(range(3), rule=rule_con_y)
+        m.con_z = Constraint(expr=m.x + m.z == -1)
+
+        m.block1 = Block()
+        m.block1.a = Var()
+        m.block1.b = Var(initialize=7)
+        m.block1.c = Var(initialize=-5)
+        m.block1.d = Var()
+
+        m.block1.con_a = Constraint(expr=m.block1.a**2 + m.block1.b == 1)
+        m.block1.con_b = Constraint(expr=m.block1.b + m.block1.c == 3)
+        m.block1.con_c = Constraint(expr=m.block1.c + m.block1.a == -4)
+        return m
+
+    @pytest.mark.unit
+    def test_verify_active_variables_initialized(self, model):
+        diag_tbx = DiagnosticsToolbox(model)
+        with pytest.raises(
+            RuntimeError,
+            match=self.err_msg(3),
+        ):
+            diag_tbx._verify_active_variables_initialized()
+
+        model.block1.deactivate()
+        with pytest.raises(
+            RuntimeError,
+            match=self.err_msg(2),
+        ):
+            diag_tbx._verify_active_variables_initialized()
+
+        model.con_y[1].deactivate()
+        model.con_z.deactivate()
+        # No uninitialized variables in remaining constraints
+        diag_tbx._verify_active_variables_initialized()
+
+    @pytest.mark.unit
+    def test_error_handling(self, model):
+        diag_tbx = DiagnosticsToolbox(model)
+        methods = [
+            "display_variables_with_extreme_jacobians",
+            "display_constraints_with_extreme_jacobians",
+            "display_extreme_jacobian_entries",
+            "display_near_parallel_constraints",
+            "display_near_parallel_variables",
+            "display_constraints_with_mismatched_terms",
+            "display_constraints_with_canceling_terms",
+            "display_constraints_with_no_free_variables",
+            "report_numerical_issues",
+        ]
+        for mthd in methods:
+            mthd_obj = getattr(diag_tbx, mthd)
+            with pytest.raises(
+                RuntimeError,
+                match=self.err_msg(3),
+            ):
+                mthd_obj()
+
+    @pytest.mark.unit
+    def test_display_problematic_constraint_terms(self, model):
+        """
+        This method needs to be split into a separate function
+        because it takes a constraint as an argument.
+        """
+        diag_tbx = DiagnosticsToolbox(model)
+        with pytest.raises(
+            RuntimeError,
+            match=self.err_msg(3),
+        ):
+            diag_tbx.display_problematic_constraint_terms(model.con_y[1])
+        # The current implementation shows an error message whether or not
+        # a problematic constraint is called.
+        with pytest.raises(
+            RuntimeError,
+            match=self.err_msg(3),
+        ):
+            diag_tbx.display_problematic_constraint_terms(model.con_y[0])
+
+    @pytest.mark.unit
+    def test_display_variables_with_none_value_in_activated_constraints(self, model):
+        diag_tbx = DiagnosticsToolbox(model)
+        stream = StringIO()
+
+        diag_tbx.display_variables_with_none_value_in_activated_constraints(
+            stream=stream,
+        )
+
+        expected = """====================================================================================
+The following variable(s) have a value of None:
+
+    y[1]
+    z
+    block1.a
+
+====================================================================================
+"""
+        assert stream.getvalue() == expected
+
+
 @pytest.mark.unit
 def test_vars_with_none_value(model):
     none_value = _vars_with_none_value(model)
@@ -976,8 +1099,8 @@ def test_display_overconstrained_set(self, model):
     def test_display_variables_with_extreme_jacobians(self):
         model = ConcreteModel()
         model.v1 = Var(initialize=1e-8)
-        model.v2 = Var()
-        model.v3 = Var()
+        model.v2 = Var(initialize=1)
+        model.v3 = Var(initialize=1)
 
         model.c1 = Constraint(expr=model.v1 == model.v2)
         model.c2 = Constraint(expr=model.v1 == 1e-8 * model.v3)
@@ -1004,8 +1127,8 @@ def test_display_variables_with_extreme_jacobians(self):
     def test_display_constraints_with_extreme_jacobians(self):
         model = ConcreteModel()
         model.v1 = Var(initialize=1e-8)
-        model.v2 = Var()
-        model.v3 = Var()
+        model.v2 = Var(initialize=1)
+        model.v3 = Var(initialize=1)
 
         model.c1 = Constraint(expr=model.v1 == model.v2)
         model.c2 = Constraint(expr=model.v1 == 1e-8 * model.v3)
@@ -1030,8 +1153,8 @@ def test_display_constraints_with_extreme_jacobians(self):
     def test_display_extreme_jacobian_entries(self):
         model = ConcreteModel()
         model.v1 = Var(initialize=1e-8)
-        model.v2 = Var()
-        model.v3 = Var()
+        model.v2 = Var(initialize=1)
+        model.v3 = Var(initialize=1)
 
         model.c1 = Constraint(expr=model.v1 == model.v2)
         model.c2 = Constraint(expr=model.v1 == 1e-8 * model.v3)
@@ -1060,8 +1183,8 @@ def test_display_extreme_jacobian_entries(self):
     def test_display_near_parallel_constraints(self):
         model = ConcreteModel()
         model.v1 = Var(initialize=1e-8)
-        model.v2 = Var()
-        model.v3 = Var()
+        model.v2 = Var(initialize=1)
+        model.v3 = Var(initialize=1)
 
         model.c1 = Constraint(expr=model.v1 == model.v2)
         model.c2 = Constraint(expr=model.v1 == 1e-8 * model.v3)
@@ -1087,9 +1210,9 @@ def test_display_near_parallel_constraints(self):
     def test_display_near_parallel_variables(self):
         model = ConcreteModel()
         model.v1 = Var(initialize=1e-8)
-        model.v2 = Var()
-        model.v3 = Var()
-        model.v4 = Var()
+        model.v2 = Var(initialize=1)
+        model.v3 = Var(initialize=1)
+        model.v4 = Var(initialize=1)
 
         model.c1 = Constraint(expr=1e-8 * model.v1 == 1e-8 * model.v2 - 1e-8 * model.v4)
         model.c2 = Constraint(expr=1e-8 * model.v1 + 1e-8 * model.v4 == model.v3)