COMSOL 6.4 - Backward Compatibility with Version 6.3 and Earlier

Backward Compatibility with Version 6.3 and Earlier

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The default in the feature has been changed from “0” to “1”, since this behavior better synchronizes with labels, tags, and other default feature properties. In addition to this — specifically for the feature in the Magnetic Fields, No Currents interface — the default force calculation method is now the . This means that this version of the feature is, strictly speaking, not compatible with previous versions of COMSOL®, considering the support of model methods, Java code, and stored MATLAB® scripts. This is because these scripts typically do not mention default settings explicitly. To patch up previously recorded code, in most cases it suffices to add instructions to set these values back to their old default:

model.physics().create("mfnc", "MagnetostaticsNoCurrents", "geom1");

model.physics("mfnc").create("fcal1", "ForceCalculation", 3);

model.physics("mfnc").feature("fcal1").set("ForceCalculationMethod", "NoForceOnContact");

model.physics("mfnc").feature("fcal1").set("ForceName", 0);

Note that the new default settings are often better than the old ones. If the script works with the new default, it is better not to revert back to the old value.

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The switch to the new default setting for the in the for the Magnetic Fields interface, the Magnetic and Electric Fields interface and the Magnetic Field Formulation interface means that this version of the is, strictly speaking, not compatible with previous versions of COMSOL®, considering the support of model methods, Java code, and stored MATLAB® scripts. This is because these scripts typically do not mention the default setting explicitly. To patch up old recordings, in most cases it suffices to add an instruction setting the mapping back to the old default:

model.physics().create("mf", "InductionCurrents", "geom1");

model.physics("mf").create("pc1", "PeriodicCondition", 3);

model.physics("mf").feature("pc1").set("meshSimilarity", "def");

Note that the new default is actually safer than the old one, since it stops solving for unreliable meshes. If the script works with the new default, it is better not to revert back to the old value.

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The switch from the old feature to the new default feature in the Electric Currents interface means that this version of the Electric Currents interface is, strictly speaking, not compatible with previous versions of COMSOL®, considering the support of model methods, Java code, and stored MATLAB® scripts. This is because these scripts typically do not mention the creation of the default feature explicitly. To patch up previously recorded code, in most cases it suffices to add a feature-create instruction right after introducing the Electric Currents interface (although migrating to "CurrentConservationSolid" or "CurrentConservationFluid" is recommended):

model.physics().create("ec", "ConductiveMedia", "geom1");

model.physics("ec").create("cucn1", "CurrentConservation", 3);

model.physics("ec").feature("cucn1").selection().all();

Note that although manual migration is recommended, most scripts will continue to work without it: Unless the model includes large structural displacements, the new default feature will function the same as the old one.