s="highlight"><pre>function cvx_optval = lambda_min_symm( X )
n = size( X, 1 );
cvx_begin
    variable y;
    maximize( y );
    subject to
        X + X&#39; - y * eye( n ) == semidefinite( n );
cvx_end
</pre></div>
</div>
<p>If a numeric value of <tt class="docutils literal"><span class="pre">X</span></tt> is supplied, this function will return
<tt class="docutils literal"><span class="pre">min(eig(X+X'))</span></tt> (to within numerical tolerances). However, this
function can also be used in CVX constrai