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_nomass_to_from_standards_dict():
"""Test the initialization of EnergyMaterialNoMass objects from standards gem."""
standards_dict = {
"name": "MAT-SHEATH",
"material_type": "MasslessOpaqueMaterial",
"roughness": None,
"thickness": None,
"conductivity": 6.24012461866438,
"resistance": 0.160253209849203,
"density": 0.0436995724033012,
"specific_heat": 0.000167192127639247,
"thermal_absorptance": 0.9,
"solar_absorptance": 0.7,
"visible_absorptance": 0.7
}
mat_1 = EnergyMaterialNoMass.from_standards_dict(standards_dict)
assert mat_1.name == 'MAT-SHEATH'
assert mat_1.roughness == 'MediumRough'
assert mat_1.r_value == pytest.approx(0.1602532098 / 5.678, rel=1e-2)
assert mat_1.thermal_absorptance == 0.9
assert mat_1.solar_absorptance == 0.7
assert mat_1.visible_absorptance == 0.7