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Arrow volume expression
Posted 21 nov. 2023, 08:11 UTC−5 RF & Microwave Engineering Version 5.6 3 Replies
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In the result temw.Hx and the coordinate x are both vectors. I want to use d(temw.Hx, x) as the expression for the arrow, so I want to take the modulus of the coordinate x and change the expression to d(temw.Hx, abs(x)). But the system reminds that x and y in d(x, y) must be variables。
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The quantities temw.Hx and x are both scalars. However, they are components of vectors 
and 
, respectively. The expression 
should give you the derivative of 
with respect to 
. For x>=0, this should be the same as the derivative with respect to abs(x). For x<0, this would simply flip the sign of the derivative. So if I were you, and if I truly needed the derivative with respect to |x|, then I would construct the derivative of temw.Hx with respect to x and (again, only if I had a good physics-based reason to do so) mutiply it by -1 for all cases where x<0. For example, 
just might do the job.
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when I do d(temw.Hz,y) - d(temw.Hy,z), d(temw.Hx,z) - d(temw.Hz,x), d(temw.Hy,x) - d(temw.Hx,y) for the x y and z components, nothing is showing up on the arrows.Do you know the reason for this?
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I suggest you post your .mph file to the forum.
-------------------Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara