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Plot a formula

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Hi,

I am trying to do simulation of resistivity changing versus deflection of a membrane. the membrane is subject to an
input pressure from range 0 to 100[kPa]. I simulate the model parametric and during the plot of any function same as resistivity, I need the value of that function in the first point of range to some calculation. How I can do this, I mean how I can do this by writting a furmolla
for example
Pressure range: (0, 10, 100) "(first point, step, end point)"
Function: V "Voltage"
I want to plot this formula:
(V-V(First point))/V(first point)

Any help will be greatly appreciated.

1 Reply Last Post 28 mars 2013, 16:44 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 28 mars 2013, 16:44 UTC−4
Hi

you need a combined approach, you define a "Point integration" on a single point, where you want to read your voltage (note that the integration over a "single point" is "just the value of this point. Then you can define a moel Definitions Variables V(first point) == myVar = intop1(V)


then you need to update your solution, or resolve, then you can use the variables just defined, in a Results derived variables ...

but to be sure to do it correctly, pls add the spatial dependences V(x,y,z) and then select the appropriate entities to average or integrate over to make the fields into global scalars
--
Good luck
Ivar
Hi you need a combined approach, you define a "Point integration" on a single point, where you want to read your voltage (note that the integration over a "single point" is "just the value of this point. Then you can define a moel Definitions Variables V(first point) == myVar = intop1(V) then you need to update your solution, or resolve, then you can use the variables just defined, in a Results derived variables ... but to be sure to do it correctly, pls add the spatial dependences V(x,y,z) and then select the appropriate entities to average or integrate over to make the fields into global scalars -- Good luck Ivar

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