Julien,

Are the sources definitely being added to the the RHS? They may be
added to the LHS, which won't work if you also have a transient term
on the LHS. Try changing the signs of the source terms.

Cheers

On Thu, Nov 8, 2012 at 11:34 AM, Julien Derr <[email protected]> wrote:
> Thank you very much Daniel.
> In the meantime, I was thinking about the alternate solution to use an
> extra variable to put my constraint by adding in my equation :
>
> ceq=CUSTOMbuildMetalIonDiffusionEquation(ionVar=c,distanceVar=phi,depositionRate=depositionRateVariable,diffusionCoeff=D)
>  - ImplicitSourceTerm(1E20*interfaceforceq) + interfaceforceq*1E20
>
>
> the second line shouldn't guarantee that the variable c will be equal
> to 1 where interfaceforeq=1 ?
> and not change anything when interfaceforeq=0 ?
>
> thanks,
>
> Julien
>
> PS because I'm not observing that, c goes to zero everywhere!
>
> On Thu, Nov 8, 2012 at 5:02 PM, Daniel Wheeler
> <[email protected]> wrote:
>>
>>
>>
>> On Wed, Nov 7, 2012 at 1:43 PM, Julien Derr <[email protected]> wrote:
>>>
>>> Hi everyone,
>>>
>>>
>>> I am using constrain in a syntax like
>>> c.constrain(1., where=facesOutside)
>>>
>>> If I want to release the constrain, Is it possible? how can I do this ?
>>
>>
>> Hi Julien,
>>
>> Yes this is possible. There is a method of the Variable class called
>> "release". All this does is remove the constraint from the variables list of
>> constraints. One issue in the case above it getting a handle on the actual
>> constraint. You'll need to use the "faceConstraints" list to do this. The
>> following will probably deal with your issue.
>>
>>   > import fipy as fp
>>   > m = fp.Grid1D()
>>   > v = fp.CellVariable(mesh=m)
>>   > v.constrain(1., where=m.facesLeft)
>>   > print v.faceValue
>>   [ 1.  0.]
>>   > v.release(v.faceConstraints[0])
>>   > print v.faceValue
>>   [ 0.  0.]
>>
>> It might be better if "constrain" returned a reference to the actual
>> constraint rather than using the "faceConstraints" attribute to get the
>> reference, but at least for now it works as described above.
>>
>> Cheers
>>
>> --
>> Daniel Wheeler
>>
>> _______________________________________________
>> fipy mailing list
>> [email protected]
>> http://www.ctcms.nist.gov/fipy
>>   [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
>>
> _______________________________________________
> fipy mailing list
> [email protected]
> http://www.ctcms.nist.gov/fipy
>   [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]



-- 
Daniel Wheeler
_______________________________________________
fipy mailing list
[email protected]
http://www.ctcms.nist.gov/fipy
  [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]

Reply via email to