Hi Jon, I think I didn't understand the operator variable completely. Thanks for pointing that out. And thank you for all the supports. Please see below an example of what I'm trying to do:
kp['NO3'] = (k['R2'] * k_O2_NO3/(k_O2_NO3 + O2.var)).copy() kp['NO3'].setValue(0.,where = Qcc == 0) So, I'd like to set the the kp['NO3'] value to be equal to k['R2'] * k_O2_NO3/(k_O2_NO3 + O2.var. But when it hits to the next time, I got the error "TypeError: The value of an `_OperatorVariable` cannot be assigned". Then, after I adding the .copy() method behind, it works. kp['NO3'] becomes a CellVariable rather than an OperatorVariable. Best regards, Rose On Mon, Feb 10, 2014 at 8:50 PM, Guyer, Jonathan E. Dr. < [email protected]> wrote: > > On Feb 8, 2014, at 11:25 AM, yuan wang <[email protected]> wrote: > > > I found that if b and c are cellvariables, the command a = b*c will make > a an operator variable. If I use a = (b * c).copy(), a becomes a > cellvariable. Would this be a good command to use to assign b*c values to > cellvariable a? > > Not really. .copy() ought to produce another operator variable. I would > not rely on the fact that it doesn't. > > What are you trying to do? Set an initial condition? > > a = CellVariable(..., value=(b * c).value) > > would be a good way, or > > a.value = (b * c).value > > after a has been declared. > > > > A general question is why we need the operator variables, if all we care > is numpy array operations and value assignment? > > Who said all we care about is numpy array operations and value assignment? > The coefficients of PDEs often depend on the fields being solved for. > Operator values allow these coefficients to evolve as the fields evolve. > > What are you actually trying to do? > _______________________________________________ > fipy mailing list > [email protected] > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] > -- Yuan (Rose) Wang PhD Candidate, Tufts University Cellphone: 617-699-8006
_______________________________________________ fipy mailing list [email protected] http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
