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<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Hello everybody,<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>I am beginning to use ADOL-C in a computational
mechanics problem which includes several conditional assignments in the
function evaluation and I have two questions regarding jacobian return values
and retaping:<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>- I suppose (because section 1.8 of ADOL-C Users
Guide doesn&#8217;t say much about it) that the optimum return value for the
jacobian evaluation is +3. However, which consequences can other return values
have? As far as I know, when the return value is negative the tape must be
regenerated, but what happens with +2 return values? I have lots of them in my
program and they don&#8217;t seem to bother the result.<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>- Then, do you have any experience regarding the
possible increase of calculation time when a frequent retaping is needed?<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Thank you very much,<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Alfonso<o:p></o:p></span></font></p>

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