From Clement.David at esi-group.com Wed Sep 13 18:02:27 2017 From: Clement.David at esi-group.com (=?utf-8?B?Q2zDqW1lbnQgRGF2aWQ=?=) Date: Wed, 13 Sep 2017 16:02:27 +0000 Subject: [Scilab-Dev] Server migration bugzilla.scilab.org / codereview.scilab.org Message-ID: <1505318546.2315.21.camel@esi-group.com> Dear users, The bugzilla / codereview server will be migrated to our new ESI-backed infrastructure. These services will be down for 24 to 48 hours ; we will do our best to minimize the down time. If you wish to submit a patch, please mail it to the dev mailing list. Sorry for the inconvenience, -- Cl?ment From jkabrg at gmail.com Mon Sep 18 19:01:36 2017 From: jkabrg at gmail.com (Ran Gutin) Date: Mon, 18 Sep 2017 18:01:36 +0100 Subject: [Scilab-Dev] Quadratic programming: Fold equality constraints into objective function? Message-ID: Hi, the quadratic programming solver qpsolve in Scilab has an argument for specifying equality constraints, while also requiring that the quadratic form $Q$ be positive definite. I've done some manipulations (similar to the ones on Wikipedia [1]), and the equality constraints can be "folded into" $Q$, so that it can go from not being positive definite to being positive definite. Could the requirement that $Q$ be positive definite be relaxed? [1] - https://en.wikipedia.org/wiki/Quadratic_programming# Equality_constraints ____ The way to "eliminate" the equality constraints $Ax = b$ is to solve $Ax = b$ by finding a vector $x_0$ and a matrix $K$ such that $Ax_0=b$ and $K$ is the kernel of $A$ (this is what the `linsolve` function does). You can then do the substitution $x = x_0 + K u$ where $u$ is an arbitrary column vector with compatible dimensions. The substitution is done inside both the objective function and the inequality constraints. The quadratic program then tries to optimize in terms of the variable $u$. Since $u$ has fewer dimensions than $x$, this results in a quadratic program with fewer dimensions. Once the optimal $u^*$ is found, compute $x^*$ by $x^* = x_0 + K u^*$. -------------- next part -------------- An HTML attachment was scrubbed... URL: From sgougeon at free.fr Sat Sep 23 12:19:48 2017 From: sgougeon at free.fr (Samuel Gougeon) Date: Sat, 23 Sep 2017 12:19:48 +0200 Subject: [Scilab-Dev] Server migration bugzilla.scilab.org / codereview.scilab.org In-Reply-To: <1505318546.2315.21.camel@esi-group.com> References: <1505318546.2315.21.camel@esi-group.com> Message-ID: Hello Cl?ment, Le 13/09/2017 ? 18:02, Cl?ment David a ?crit : > Dear users, > > The bugzilla / codereview server will be migrated to our new ESI-backed infrastructure. These > services will be down for 24 to 48 hours ; we will do our best to minimize the down time. > > If you wish to submit a patch, please mail it to the dev mailing list. Thanks a lot for having restored both services this week. However, for both bugzilla and codeReview, mailed notifications look to still be down. Best regards Samuel