Hi Michela, It looks like you're referring to JuMP, in which case:
@defVar(m, a <= x <= b, SemiCont) should do the trick. See also the documentation: http://jump.readthedocs.org/en/release-0.8/refvariable.html?highlight=semicontinuous We prefer to direct optimization-related questions to julia-opt <https://groups.google.com/forum/#!forum/julia-opt>, for future reference. Best, Miles On Monday, March 30, 2015 at 3:36:15 PM UTC-4, Kevin Squire wrote: > > Hi Michela, > > I think you're going to need to provide some additional information. Are > you modeling this in JuMP by chance? > > Cheers, > Kevin > > On Mon, Mar 30, 2015 at 12:25 PM, Michela Di Lullo <michela...@uniroma1.it > <javascript:>> wrote: > >> Hallo everyone! >> >> how do I model a variable (array of variables) that can either be zero or >> in some range not containing zero? >> e.g. x∈0∪[a,b] where a>0 >> >> Thank you in advance for any information! >> >> Michela >> > >
