Re: [R] Quadratic Optimization

2006-12-02 Thread Martin Maechler
SpG == Spencer Graves [EMAIL PROTECTED] on Fri, 01 Dec 2006 17:29:56 -0800 writes: SpG Unless I'm missing something, optimizing a linear SpG function with quadratic constraints is almost trivial SpG with Langrange multipliers. yes. Good point, let's hope we're not solving

Re: [R] Quadratic Optimization

2006-12-02 Thread Prof Brian Ripley
On Sat, 2 Dec 2006, Martin Maechler wrote: SpG == Spencer Graves [EMAIL PROTECTED] on Fri, 01 Dec 2006 17:29:56 -0800 writes: SpG Unless I'm missing something, optimizing a linear SpG function with quadratic constraints is almost trivial SpG with Langrange multipliers.

Re: [R] Quadratic Optimization

2006-12-02 Thread Spencer Graves
Hi, Prof. Ripley: snip But that is a single equality quadratic constraint, and I believe 'quadratic constraints' (note, plural) conventionally means multiple inequality constraints. That meaning is a hard problem that needs specialized software (most likely using interior-point

Re: [R] Quadratic Optimization

2006-12-02 Thread amit soni
: Saturday, December 2, 2006 1:19:06 PM Subject: Re: [R] Quadratic Optimization Hi, Prof. Ripley: snip But that is a single equality quadratic constraint, and I believe 'quadratic constraints' (note, plural) conventionally means multiple inequality constraints. That meaning is a hard problem

Re: [R] Quadratic Optimization

2006-12-01 Thread Spencer Graves
Unless I'm missing something, optimizing a linear function with quadratic constraints is almost trivial with Langrange multipliers. Maximize a'x subject to x'Ax=c. S = Lagrange objective = a'x+lam*(x'Ax-c). dS/dx = a + 2*lam*Ax. Given lam, x1 = solve(A,

[R] Quadratic Optimization

2006-11-27 Thread amit soni
Hi, I need to solve an optimization problem in R having linear objective function and quadratic constraints(number of variables is around 80). What are the possible choices to do this in R. optim() function only allows box constrained problems. Is it possible in nlm()? Or please tell me if