Re: Linear Programming constraint

*To*: mathgroup at smc.vnet.net*Subject*: [mg28552] Re: Linear Programming constraint*From*: "Allan Hayes" <hay at haystack.demon.co.uk>*Date*: Fri, 27 Apr 2001 03:56:06 -0400 (EDT)*References*: <9c7mcr$sbc@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Pramod, ConstrainedMin[x + 3*y + 7*z, {x - 3*y < 7 && 2*x + 3*z >= 5 || x + y + z >= 1}, {x, y, z}] ConstrainedMin::cmeq:{} is not a valid equation or inequality. So split into two probems: cond = LogicalExpand[x - 3*y < 7 && 2*x + 3*z >= 5 || x + y + z >= 1] 2*x + 3*z >= 5 && x - 3*y < 7 || x + y + z >= 1 (ConstrainedMin[x + 3*y + 7*z, #1, {x, y, z}] & ) /@ cond {5/2, {x -> 5/2, y -> 0, z -> 0}} || {1, {x -> 1, y -> 0, z -> 0}} Take the solution giving the least minimum Sort[%] {1, {x -> 1, y -> 0, z -> 0}} || {5/2, {x -> 5/2, y -> 0, z -> 0}} First[%] {1, {x -> 1, y -> 0, z -> 0}} You could refine the program to give which of the Or constraints are satisfied. -- Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK www.haystack.demon.co.uk hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565 "Pramod" <pramod at svw.com> wrote in message news:9c7mcr$sbc at smc.vnet.net... > > Hi, > > I have an LP problem with 6 constraints > > The problem is that last two constraints are OR constraints - not like > other AND constraints > ie., x1 < 40 OR x1 > 60 > Making it clear, the system should find optimal values for all > variables, but the value of x1 should'nt be between 40 & 60 > > How can i convert it to one or more AND constraints and add them to the > rest of the constraints ? > > Please help me !! > > Thanks in Advance > > Pramod > > >