def opaque_material_by_name(material_name):
"""Get an opaque material from the library given the material name.
Args:
material_name: A text string for the name of the material.
"""
try: # see if the material has already been loaded to a Python object
return _idf_opaque_materials[material_name]
except KeyError: # material likely needs to be loaded from standards data
try:
_mat_dict = _opaque_standards_dict[material_name]
except KeyError: # material is nowhere to be found; raise an error
raise ValueError(
'"{}" was not found in the opaque energy material library.'.
format(material_name))
# create the Python object from the standards gem dictionary
if _mat_dict['material_type'] == 'StandardOpaqueMaterial':
_mat_obj = EnergyMaterial.from_standards_dict(_mat_dict)
elif _mat_dict['material_type'] in ('MasslessOpaqueMaterial', 'AirGap'):
_mat_obj = EnergyMaterialNoMass.from_standards_dict(_mat_dict)
else:
raise ValueError(
'Standards gem material type "{}" is not recognized.'.format(
_mat_dict['material_type']))
_mat_obj.lock()
_idf_opaque_materials[
material_name] = _mat_obj # next time, it will be loaded faster
return _mat_obj
def test_material_to_from_standards_dict():
"""Test the initialization of EnergyMaterial objects from standards gem."""
standards_dict = {
"name": "Extruded Polystyrene - XPS - 6 in. R30.00",
"material_type": "StandardOpaqueMaterial",
"roughness": "MediumSmooth",
"thickness": 6.0,
"conductivity": 0.20,
"resistance": 29.9999994,
"density": 1.3,
"specific_heat": 0.35,
"thermal_absorptance": None,
"solar_absorptance": None,
"visible_absorptance": None
}
mat_1 = EnergyMaterial.from_standards_dict(standards_dict)
assert mat_1.name == 'Extruded Polystyrene - XPS - 6 in. R30.00'
assert mat_1.thickness == pytest.approx(0.1524, rel=1e-3)
assert mat_1.conductivity == pytest.approx(0.028826, rel=1e-3)
assert mat_1.density == pytest.approx(20.82, rel=1e-3)
assert mat_1.specific_heat == pytest.approx(1464.435, rel=1e-3)
assert mat_1.roughness == 'MediumSmooth'
assert mat_1.resistivity == pytest.approx(1 / 0.028826, rel=1e-3)
