Hi Francis, <div>   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.</div><div>All the best</div><div>Cjc<br><br>On Friday, 17 June 2016, Francis Poulin &lt;<a href="mailto:fpoulin@uwaterloo.ca">fpoulin@uwaterloo.ca</a>&gt; wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">




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<div style="direction:ltr;font-family:Tahoma;color:#000000;font-size:10pt">Hello,<br>
<br>
I want to define an initial condition for a field that I am pretty sure will have nan&#39;s.  It does in python so I&#39;m pretty sure that it will in firedrake as well.<br>
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In python I know how to remove that nan&#39;s by doing the following.<br>
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qb[np.isnan(qb)] = 0. <br>
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<div>Is there a way of doing this in firedrake?<br>
<br>
Cheers, Francis<br>
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Francis Poulin                    <br>
Associate Professor<br>
Department of Applied Mathematics<br>
University of Waterloo<br>
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email:           <a href="javascript:_e(%7B%7D,&#39;cvml&#39;,&#39;fpoulin@uwaterloo.ca&#39;);" target="_blank">fpoulin@uwaterloo.ca</a><br>
Web:            <a href="https://uwaterloo.ca/poulin-research-group/" target="_blank">https://uwaterloo.ca/poulin-research-group/</a><br>
Telephone:  +1 519 888 4567 x32637<br>
<br>
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