Hi Francis, If you can predict the situations under which you get divide by zero, then you can use the ?: operator in an Expression string or Condition in ufl. All the best Cjc On Friday, 17 June 2016, Francis Poulin <fpoulin@uwaterloo.ca> wrote:

Hello,

I want to define an initial condition for a field that I am pretty sure will have nan's. It does in python so I'm pretty sure that it will in firedrake as well.

In python I know how to remove that nan's by doing the following.

qb[np.isnan(qb)] = 0.

Is there a way of doing this in firedrake?

Cheers, Francis

------------------ Francis Poulin Associate Professor Department of Applied Mathematics University of Waterloo

email: fpoulin@uwaterloo.ca <javascript:_e(%7B%7D,'cvml','fpoulin@uwaterloo.ca');> Web: https://uwaterloo.ca/poulin-research-group/ Telephone: +1 519 888 4567 x32637

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