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Derivate of a dependent variable is 0

Posted Mar 24, 2012, 11:34 a.m. EDT Modeling Tools & Definitions, Parameters, Variables, & Functions, Results & Visualization Version 4.2a 2 Replies

Francesc-Xavier Borras
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Hi,

I am having a really dumb problem. I am doing something wrong.

I apply a physic(Lubrication Shell) and the output is a pressure distribution. I need the derivate of this pressure respect x and y.

d(pf,x)
d(pf,y)

When I plot it,the result is always null. Is it derivating a constant?

What I am doing wrong? I attach a file just to show it but it is really easy to do it.
2 Replies Last Post Mar 26, 2012, 5:31 p.m. EDT
Francesc-Xavier Borras
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Posted: 1 decade ago Mar 26, 2012, 1:40 p.m. EDT
I don't know if it is too basic and people dont want to answer or it is something really dificult...
I don't know if it is too basic and people dont want to answer or it is something really dificult...
Nagi Elabbasi Facebook Reality Labs
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Posted: 1 decade ago Mar 26, 2012, 5:31 p.m. EDT
Use dtang(pf,x) instead since pf is only defined on a boundary.
Use dtang(pf,x) instead since pf is only defined on a boundary.

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