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Viewing weak equations

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Is there any way to view the weak form equations that COMSOL generates from the coefficient form PDE interface? If there is an error in the compilation, the error message will have the weak form equations in it so I know they are generated internally somewhere. Is there some way to view them?
Thanks.


2 Replies Last Post 2011年11月29日 GMT-5 02:47
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2011年11月29日 GMT-5 01:35
Hi

to loo under the hood, turn on the "equation view sub nodes" in the preferences

--
Good luck
Ivar
Hi to loo under the hood, turn on the "equation view sub nodes" in the preferences -- Good luck Ivar

Magnus Ringh COMSOL Employee

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Posted: 1 decade ago 2011年11月29日 GMT-5 02:47
Hi,

Although the Equation View in almost all cases displays the weak expressions that the physics interfaces generate, the Coefficient Form PDE interface is different in that its equations are implemented in the "strong" coeffient form directly, so there are no "weak expressions" in its Equation View.

It's hard to say why you would get an error in the multiphysics compilation, but typical errors include syntax errors in the definitions of the PDE coefficients and failures to evaluate a variable that is undefined (could be a simple typographical error, for example). In those cases, the displayed error includes information about the source of the problem, including the compiled weak formulation as you have noticed. Hopefully that information can point you in the right direction for troubleshooting the model.

Best regards,
Magnus Ringh, COMSOL
Hi, Although the Equation View in almost all cases displays the weak expressions that the physics interfaces generate, the Coefficient Form PDE interface is different in that its equations are implemented in the "strong" coeffient form directly, so there are no "weak expressions" in its Equation View. It's hard to say why you would get an error in the multiphysics compilation, but typical errors include syntax errors in the definitions of the PDE coefficients and failures to evaluate a variable that is undefined (could be a simple typographical error, for example). In those cases, the displayed error includes information about the source of the problem, including the compiled weak formulation as you have noticed. Hopefully that information can point you in the right direction for troubleshooting the model. Best regards, Magnus Ringh, COMSOL

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