VX &#8212; that is, when its argument is numerical. But thanks to Matlab&#8217;s
operator overloading capability, it will also work within CVX if
called with an affine argument. CVX will properly conclude that the
function is convex, because all of the operations carried out conform to
the rules of DCP: <tt class="docutils literal"><span class="pre">abs</span></tt> is recognized as a convex function; we can
subtract a constant from it, and we can take the maximum of the result
and <tt class="docutils litera