Merge pull request OpenMDAO#3387 from swryan/2711_set_input_defaults

Added additional documentation for the `set_input_defaults` function

openmdao/core/group.py

@@ -1974,6 +1974,17 @@ def _resolve_group_input_defaults(self, show_warnings=False):
                                 abs_in2prom_info[tgt][tree_level] = \
                                     _PromotesInfo(src_shape=src_shape, prom=prom,
                                                   promoted_from=self.pathname)
+                else:
+                    # check for discrete targets
+                    for tgt in prom2abs_in[prom]:
+                        if tgt in self._discrete_inputs:
+                            for key, val in meta.items():
+                                # for discretes we can only set the value (not units/src_shape)
+                                if key == 'val':
+                                    self._discrete_inputs[tgt] = val
+                                elif key in ('units', 'src_shape'):
+                                    self._collect_error(f"{self.msginfo}: Cannot set '{key}={val}'"
+                                                        f" for discrete variable '{tgt}'.")
 
                 meta.update(fullmeta)
 

openmdao/core/tests/test_group.py

@@ -3161,6 +3161,109 @@ def test_conflicting_val(self):
            "promoted input 'x' with conflicting values for 'val'. Call <group>.set_input_defaults('x', val=?), "
            "where <group> is the model to remove the ambiguity.")
 
+    def test_set_input_defaults_discrete(self):
+        import math
+        import openmdao.api as om
+
+        density = {
+            'steel': 7.85,  # g/cm^3
+            'aluminum': 2.7  # g/cm^3
+        }
+
+        class SquarePlate(om.ExplicitComponent):
+            """
+            Calculate the weight of a square plate.
+
+            material is a discrete input (default: steel)
+            """
+
+            def setup(self):
+                self.add_discrete_input('material', 'steel')
+
+                self.add_input('length', 1.0, units='cm')
+                self.add_input('width', 1.0, units='cm')
+                self.add_input('thickness', 1.0, units='cm')
+
+                self.add_output('weight', 1.0, units='g')
+
+            def compute(self, inputs, outputs, discrete_inputs, discrete_outputs):
+                length = inputs['length']
+                width = inputs['width']
+                thickness = inputs['thickness']
+                material = discrete_inputs['material']
+
+                outputs['weight'] = length * width * thickness * density[material]
+
+        class CirclePlate(om.ExplicitComponent):
+            """
+            Calculate the weight of a circular plate.
+
+            material is a discrete input (default: aluminum)
+            """
+
+            def setup(self):
+                self.add_discrete_input('material', 'aluminum')
+
+                self.add_input('radius', 1.0, units='cm')
+                self.add_input('thickness', 1.0, units='g')
+
+                self.add_output('weight', 1.0, units='g')
+
+            def compute(self, inputs, outputs, discrete_inputs, discrete_output):
+                radius = inputs['radius']
+                thickness = inputs['thickness']
+                material = discrete_inputs['material']
+
+                outputs['weight'] =  math.pi * radius**2 * thickness * density[material]
+
+        #
+        # first check that we get errors when using invalid args to set defaults on a discrete
+        #
+        p = om.Problem()
+        model = p.model
+
+        model.add_subsystem('square', SquarePlate(), promotes_inputs=['material'])
+        model.add_subsystem('circle', CirclePlate(), promotes_inputs=['material'])
+
+        # setting input defaults for units/src_shape is not valid for a discrete and will generate errors
+        model.set_input_defaults('material', 'steel', units='kg', src_shape=(1,))
+        expect_errors = [
+            f"Collected errors for problem '{p._get_inst_id()}':",
+            "   <model> <class Group>: Cannot set 'units=kg' for discrete variable 'circle.material'.",
+            "   <model> <class Group>: Cannot set 'src_shape=(1,)' for discrete variable 'circle.material'.",
+            "   <model> <class Group>: Cannot set 'units=kg' for discrete variable 'square.material'.",
+            "   <model> <class Group>: Cannot set 'src_shape=(1,)' for discrete variable 'square.material'.",
+        ]
+
+        with self.assertRaises(Exception) as cm:
+            p.setup()
+
+        err_msgs = cm.exception.args[0].split('\n')
+        for err_msg in expect_errors:
+            self.assertTrue(err_msg in err_msgs,
+                            err_msg + ' not found in:\n' + cm.exception.args[0])
+
+        #
+        # now make sure that setting just the default value for a discrete works as expected
+        #
+        p = om.Problem()
+        model = p.model
+
+        model.add_subsystem('square', SquarePlate(), promotes_inputs=['material'])
+        model.add_subsystem('circle', CirclePlate(), promotes_inputs=['material'])
+
+        model.set_input_defaults('material', 'steel')
+
+        p.setup()
+        p.run_model()
+
+        inputs = model.list_inputs(return_format='dict', out_stream=None)
+        self.assertEqual(inputs['square.material']['val'], 'steel')
+        self.assertEqual(inputs['circle.material']['val'], 'steel')
+
+        assert_near_equal(p['square.weight'], 7.85)
+        assert_near_equal(p['circle.weight'], 24.66150233, 1e-6)
+
 
 class MultComp(om.ExplicitComponent):
     """

openmdao/docs/openmdao_book/features/core_features/running_your_models/main.ipynb

@@ -7,6 +7,7 @@
     "# Running Your Models\n",
     "\n",
     "- [Setting and Getting Component Variables](set_get.ipynb)\n",
+    "- [Using 'set_input_defaults'](set_input_defaults.ipynb)\n",
     "- [Setup Your Model](setup.ipynb)\n",
     "- [Run Your Model](run_model.ipynb)\n",
     "- [Run a Driver](run_driver.ipynb)"
@@ -30,7 +31,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.5"
+   "version": "3.12.6"
   },
   "orphan": true
  },

openmdao/docs/openmdao_book/features/core_features/running_your_models/set_get.ipynb

@@ -641,14 +641,9 @@
     "to the same name as an output, then again the framework will connect all of those inputs to an\n",
     "`_auto_ivc` output.  If, however, there is any difference between the units or values of any of those inputs,\n",
     "then you must tell the framework what units and/or values to use when creating the corresponding\n",
-    "`_auto_ivc` output.  You do this by calling the `set_input_defaults` function using the promoted\n",
+    "`_auto_ivc` output.  You do this by calling the [set_input_defaults](./set_input_defaults.ipynb) function using the promoted\n",
     "input name on a Group that contains all of the promoted inputs.\n",
     "\n",
-    "```{eval-rst}\n",
-    "    .. automethod:: openmdao.core.group.Group.set_input_defaults\n",
-    "        :noindex:\n",
-    "```\n",
-    "\n",
     "Below is an example of what you'll see if you do *not* call `set_input_defaults` to disambiguate\n",
     "your units and/or values:"
    ]
@@ -1088,7 +1083,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.5"
+   "version": "3.12.6"
   },
   "orphan": true
  },