Hi everyone,<br><br>I&#39;ve recently discovered GiNaC and I&#39;m really excited about its capabilities. There is one thing that I would like to know if it is able to do that I haven&#39;t found in the tutorial.pdf or in any other place that I&#39;ve searched.<br>
<br>I would like to know if, given a function \Psi=\Psi(E), like the strain energy function for the St. Venant-Kirchhoff material<br><br>\Psi(E) = 0.5 * \lambda * (tr E)^2 + \mu E:E<br><br>is it possible to differentiate it with respect to E, that is i would like to compute \frac{\partial \Psi}{\partial E}. If this is possible, could someone please send some examples or maybe point to which classes should I use to do that?<br>
<br>That&#39;s all for now. Many thanks in advance.<br><br>Best regards,<br>Bernardo M. R.<br><br><br>