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Error in user-defined matlab function

Posted Oct 10, 2013, 4:06 a.m. EDT Interfacing, Parameters, Variables, & Functions Version 4.3 1 Reply

Yunxiang Pan
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I am using COMSOL matlab function, and I defined two functions: full_expression_PL(T,z), full_expression_PL_dT(T,z), where full_expression_PL_dT is the derivative respect to T of full_expression_PL. I clicked the Plot, the two functions can be showed successfully. However, when I compute the model, here comes an error:

Error in user-defined function.
- Function: dfull_expression_PL_dT
Failed to evaluate expression.
- Expression: d(d((2*test(mod1.Te)*mod1.Irzt*full_expression_PL(mod1.Te,z)*pi*r)*(dvol),{test@0}),mod1.Te)

The attached file is the Screenshot of the matlab function definition window.

Is there anything wrong in the definition? Does anyone know why this happens?

Thanks!
1 Reply Last Post Oct 17, 2013, 7:05 a.m. EDT
Lars Gregersen COMSOL Employee

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Posted: 1 decade ago Oct 17, 2013, 7:05 a.m. EDT
Hi

Its hard to give advise without seeing your m-files.

My guess is that dfull_expression_PL_dT has an error. Have you tried to call it with arguments consisting of column vectors (with suitable values).

Also from the error message it seems as if you also need the second derivative.


Lars Gregersen
Comsol Denmark
Hi Its hard to give advise without seeing your m-files. My guess is that dfull_expression_PL_dT has an error. Have you tried to call it with arguments consisting of column vectors (with suitable values). Also from the error message it seems as if you also need the second derivative. Lars Gregersen Comsol Denmark

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