## contour fieldmap - Mem protection fault

General discussions about how to formulate a script for FlexPDE.

### contour fieldmap - Mem protection fault

I try to change script below. I come across, a problem "Mem protection fault".
Script is not my. I try change x to y, and y to x, and i do not change others thing.
At line market '1' contour fieldmap(u) work corectly, but if i change to '2' they not.
Can you tell me in this case what is not corectly ?

Code: Select all
`title 'Plate capacitor' variables u definitions Lx=1      Ly=1 delx=0.5     d=0.2 ddy=0.2*d Ex=-dx(u)     Ey=-dy(u) eps0=8.854e-12 eps equations u : div(-eps*grad(u)) = 0 boundaries ! 1 and 2 - Region 1    eps=eps0   start "V0" (-Lx,-Ly)  Load(u)=0   line to (Lx,-Ly) to (Lx,Ly) to (-LX,Ly) to close !2start "V1" (-d/2, -delx/2) value(u)=0line to (-d/2, delx/2) to (-d/2-ddy, delx/2) to (-d/2-ddy, -delx/2) line to close{!1  start "V1" (-delx/2,-d/2)  value(u)=0    line to (delx/2,-d/2) to (delx/2,-d/2-ddy) to (-delx/2,-d/2-ddy)   to close }!2start "V2" ( d/2+ddy, -delx/2) value(u)=1line to (d/2+ddy, delx/2) to (d/2 , delx/2) to (d/2 , -delx/2) to close{ !1  start(-delx/2,d/2+ddy)       value(u)=1   line to (delx/2,d/2+ddy) to (delx/2,d/2) to(-delx/2,d/2)  to close}!2region 2 eps = 7.0*eps0 start(-d/2, -delx/2) line to (-d/2, delx/2) to (d/2 , delx/2) to (d/2, -delx/2) to close{ !1Region 2    eps = 7.0*eps0   start(-delx/2,-d/2)   line to (delx/2,-d/2) to (delx/2,d/2) to(-delx/2,d/2)         to close }monitors   contour(u) plots   contour(u)   surface(u)   vector(dx(u),dy(u)) norm   vector(dx(u),dy(u))    ! Work only when 2 is On. On 1 not.   !fieldmap(u) on "V1" fieldlines=40 as "Field Map"   !contour fieldmap(u) on "V2" fieldlines=40 points=400 as "Potential and Field Map"end `
zygi151

Posts: 9
Joined: Mon Aug 27, 2018 6:01 am

### Re: contour fieldmap - Mem protection fault

The things you have done look completely valid, so there may be an error in FlexPDE. We will have to dig into it and discover what is happening.
For now, just stick with the XY in the original order?
moderator

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### Re: contour fieldmap - Mem protection fault

We have found an error in the generation of field map contour generation. We have fixed this in v719x6 and posted a pre-release at http://www.pdesolutions.com/download/xf ... 6win64.exe. This is a self extracting archive of just the executables, not a full install. Extract the files and copy them over your current installation. If you need a Linux or Mac version, please let us know.

This fix will be present in the formal release of v719 which we will plan on publishing early next week. Thank you for bringing this to our attention.
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### Re: contour fieldmap - Mem protection fault

You`re quick...wow...
I see other protect fault is under.
Please check that, it is too when you rotation x to y

Code: Select all
`title 'Plate capacitor'variablesudefinitionsLx=1      Ly=1delx=0.5     d=0.2ddy=0.2*dEx=-dx(u)     Ey=-dy(u)eps0=8.854e-12epsequationsu : div(-eps*grad(u)) = 0boundaries! 1 and 2 -Region 1   eps=eps0  start "V0" (-Lx,-Ly) ! Load(u)=1  line to (Lx,-Ly) to (Lx,Ly) to (-LX,Ly) to close  start "V1" (-delx/2,-d/2)    value(u)=1 ! here   line to (delx/2,-d/2) to (delx/2,-d/2-ddy) to (-delx/2,-d/2-ddy)   to close  start(-delx/2,d/2+ddy)         value(u)=1 ! here  line to (delx/2,d/2+ddy) to (delx/2,d/2) to(-delx/2,d/2)  to closeRegion 2   eps = 7.0*eps0   start(-delx/2,-d/2)  line to (delx/2,-d/2) to (delx/2,d/2) to(-delx/2,d/2)         to closemonitors  contour(u)plots  contour(u)  surface(u)  vector(dx(u),dy(u)) norm   vector(dx(u),dy(u))   ! Work only when 2 is On. On 1 not.   fieldmap(u) on "V1" fieldlines=40 as "Field Map"   contour fieldmap(u) on "V1" fieldlines=40 points=400 as "Potential and Field Map"fieldmap(u) on "V0" fieldlines=40 as "Field Map"   contour fieldmap(u) on "V0" fieldlines=40 points=400 as "Potential and Field Map"   end `

I expect non field...
zygi151

Posts: 9
Joined: Mon Aug 27, 2018 6:01 am

### Re: contour fieldmap - Mem protection fault

This appears to be because there is no field. Your voltages are the same on the two plates.

Clearly FlexPDE shouldn't get a memory protection fault when there is no field. We will look at it and repair it in v7.20. Thanks for bringing this to our attention.
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