<story><title>Matrix Calculus</title><url>http://www.matrixcalculus.org</url></story><parent_chain></parent_chain><comment><author>lliiffee</author><text>For those who might not realize how amazing this is, take a look at how you can do these things manually:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;tminka.github.io&amp;#x2F;papers&amp;#x2F;matrix&amp;#x2F;minka-matrix.pdf&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;tminka.github.io&amp;#x2F;papers&amp;#x2F;matrix&amp;#x2F;minka-matrix.pdf&lt;/a&gt;</text></comment>
<story><title>Matrix Calculus</title><url>http://www.matrixcalculus.org</url></story><parent_chain></parent_chain><comment><author>Klasiaster</author><text>I can see that x&amp;#x27; means $x^T$ (x transposed) but it&amp;#x27;s not mentioned in the documentation — where does this notation come from?</text></comment>