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General form is not equivalent to Coefficient form, right?

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I read the documentation, where it's claimed the two PDE forms are equivalent and conversion from Coefficient to General form is explicitly provided. However, I find, for my case, the equation can only be put into General form. Furthermore, when I use General form to express the equation, there's no option in Model Settings to convert it to Coefficient form.

So I guess the two forms are not equivalent, am I right?

Thanks!

2 Replies Last Post 15 feb 2012, 11:49 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 15 feb 2012, 10:07 GMT-5
Hi

I understand they are equivalent but the conversion is done internally, so I do not know of any way to convert the general to coefficient form via COMSOL explicitely.

But if you can enter your equation in one or the other form, then COMSOL should solve it, provided you have enough BC's to make the solution unique

--
Good luck
Ivar
Hi I understand they are equivalent but the conversion is done internally, so I do not know of any way to convert the general to coefficient form via COMSOL explicitely. But if you can enter your equation in one or the other form, then COMSOL should solve it, provided you have enough BC's to make the solution unique -- Good luck Ivar

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Posted: 1 decade ago 15 feb 2012, 11:49 GMT-5
Hi,

Thanks for your reply!

Attached is the equation I want to solve. I do input it with General form, but don't find a way to input it with Coefficient form.
Hi, Thanks for your reply! Attached is the equation I want to solve. I do input it with General form, but don't find a way to input it with Coefficient form.

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