Re: solving set of inequalities

[Petr Korviny]

Thanks a lot for quick answers.

"jwe" you are right, that's exactly my problem.
I have got no objective function to minimize or maximize and all functions I 
have found
in Octave require objective coefficients, the "glpk" too.

I'll try mentioned "octave-sp", I'm running Ubuntu, and this package is still 
in repositories for octave3.0 version.

Thanks again to all.

Petr


On 23.1.2010 22:09, John W. Eaton wrote:
> On 23-Jan-2010, Jaroslav Hajek wrote:
>
> | On Sat, Jan 23, 2010 at 8:05 PM, mat95pat<address@hidden>  wrote:
> |>
> |>  Hi, I'd like to solve set of inequalities with Octave, but I have no idea 
> how
> |>  to do that. For example:
> |>
> |>  x1 + 2x2<= 0
> |>  2x1 + 3x3<= 0
> |>  x2 - x3<= 0
> |>  x1 + x2 + x3<=0
> |>
> |>  Does anybody know some function for solving this kind of problem, or method
> |>  with Octave?
> |>  Is possible to do that with Octave?
> |>
> |>  Thanks in advance
> |>  Petr
> |>  --
> |
> | This is called linear programming, see "glpk".
>
> What does glpk do if there is no objective to minimize?  I.e., the C
> vector is all zeros?  I don't think it can solve a set of
> inequalities.
>
> There is a package for semidefinite programming that was once ported
> to Octave.  It is still packaged for Debian as octave-sp.  I don't
> know whether it is currently maintained.
>
> jwe