Simplex optimizers as well (amoeba).. <br><br>But as Dan mentioned, you could try a finite differencing scheme.<br><br><div class="gmail_quote">On Tue, May 5, 2009 at 1:14 PM, Dan Mueller <span dir="ltr"><<a href="mailto:dan.muel@gmail.com">dan.muel@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi Huanxiang,<br>
<div class="im"><br>
> I’d like to know if there is an optimizer in ITK which is derivative free.<br>
</div>OnePlusOneEvolutionaryOptimizer does not use the gradient.<br>
<div class="im"><br>
<br>
> Or is there any other way to calculate the derivative value?<br>
</div>Have you tried a simple finite difference approach?<br>
For an example have a look at the function fdgrad(..)<br>
Utilities\vxl\core\vnl\vnl_cost_function.cxx<br>
<br>
Hope this helps.<br>
<br>
Regards, Dan<br>
<br>
2009/5/5 Huanxiang Lu <<a href="http://huanxiang.lu" target="_blank">huanxiang.lu</a>@<a href="http://artorg.unibe.ch" target="_blank">artorg.unibe.ch</a>>:<br>
<div><div></div><div class="h5">> Hello,<br>
><br>
><br>
><br>
> I am creating a new metric using CUDA implementation. So far I found it is<br>
> very difficult to get the derivative value from my implementation. I’d like<br>
> to know if there is an optimizer in ITK which is derivative free. Or is<br>
> there any other way to calculate the derivative value?<br>
><br>
><br>
><br>
> Thanks a lot!<br>
><br>
><br>
><br>
> Huanxiang Lu<br>
><br>
><br>
><br>
><br>
><br>
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</blockquote></div><br><br clear="all"><br>-- <br>Karthik Krishnan<br>R&D Engineer,<br>Kitware Inc.<br>Ph: 518 881 4919<br>Fax: 518 371 4573<br>