User artem pyanykh - MathOverflowmost recent 30 from http://mathoverflow.net2013-05-19T01:33:12Zhttp://mathoverflow.net/feeds/user/29762http://www.creativecommons.org/licenses/by-nc/2.5/rdfhttp://mathoverflow.net/questions/115751/convex-optimization-problem-to-qppConvex optimization problem to QPPArtem Pyanykh2012-12-07T21:57:16Z2012-12-09T18:11:27Z
<p>Briefly, have the following problem:
\begin{equation}
\sum_{i = 0}^n a_i \ (max [ F_i( \bar x ), 0 ] )^2 \rightarrow min, \\
s.t.\\
A \bar x \leq b
\end{equation}
where $ F( \bar x ) $ is a linear function, $a_i \gt 0$, $n$ is huge comparing to the size of $x$.</p>
<p>It is possible to write an equal Quadratic Programming problem, such as</p>
<p>$$
\sum_{i=0}^n a_i \ ( G_i )^2 \rightarrow min \\
s.t. \\
G_i \geq {\bf 0}, \quad i = 0..n \\
G_i \geq F_i( \bar x ) \quad i = 0..n \\
A \bar x \leq b
$$</p>
<p>which can be solved very efficiently with an appropriate numerical method.</p>
<p>Unfortunately in my particular case such conversion doesn't work: it adds a lot of new restrictions, and that appropriate numerical method doesn't converge. </p>
<p>I tried to figure out another equal QPP, which adds fewer new constraints, but nothing came across my mind. Is there another way?</p>
<p><strong>Edit</strong>: I need some time to apply both methods to my particular problem. I'll try to report on result as soon as I can.</p>
http://mathoverflow.net/questions/115751/convex-optimization-problem-to-qppComment by Artem PyanykhArtem Pyanykh2012-12-08T16:38:26Z2012-12-08T16:38:26Z@fedja all $a_i$ is positive; n can be huge comparing to size of vector $\hat x$, e.g. size($x$) = s, then n is around $c p^s$, where c p is some positive constants.http://mathoverflow.net/questions/115751/convex-optimization-problem-to-qppComment by Artem PyanykhArtem Pyanykh2012-12-08T14:08:40Z2012-12-08T14:08:40Z@fedja Yep! Apologize for being not enougn specific. I edited the question. As for a LPP, I can't find a way to transform this problem to lunear programming problem now.