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Conditional Expressions

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Hi All,

I was wondering if there is a way to make a dependent variable's expression be different depending on the value of another dependent variable.

For example, suppose we have the expression
ut-u=0

and wanted
y-u^2 = 0
for some u, but
y-u^3 = 0
for other u values.

Is there a way to do that?

Thanks for any advice in advance,

3 Replies Last Post 28 sept. 2012, 14:33 UTC−4
Nagi Elabbasi Facebook Reality Labs

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Posted: 1 decade ago 28 sept. 2012, 11:53 UTC−4
You can setup expressions such as this (y-u^2)*(u<2)+(y-u^3)*(u>=2)
You can setup expressions such as this (y-u^2)*(u=2)

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Posted: 1 decade ago 28 sept. 2012, 14:18 UTC−4
I see, so to make sure I understand, COMSOL evaluates inequalities as 0 if they are false, and 1 if they are true? Or is it -1 if they are false?
I see, so to make sure I understand, COMSOL evaluates inequalities as 0 if they are false, and 1 if they are true? Or is it -1 if they are false?

Nagi Elabbasi Facebook Reality Labs

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Posted: 1 decade ago 28 sept. 2012, 14:33 UTC−4
0 if false 1 if true
0 if false 1 if true

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