Gunter,<br><br>Actually I got confused because you said both push_back and append_element. Anyway, I tried both. append_element is 100 times slower than an ublas::matrix with +=s. I don&#39;t know what I&#39;m doing wrong (sorry if there&#39;s something really stupid there). Please take a look at the source attached.<br>
<br>Thank you.<br><br><br>x<br>