Re: [Help-glpk] TRANSPORTATION PROBLEM

[Andrew Makhorin]

> Hi guys, Im working on a transportation problem, the problem to model
> is the following one,

> Minimize Z = sum{from i=1 to m}sum{from j=1 to n} of Cij * Xij

> i belongs to N = {1,2, ..., m}
> j belongs to J = {1,2,..., n}

> Cij is the distance from an apple tree to a  bin

> RESTRICTIONS

> sum{from j = 1 to n} of Xij = 1 , i = 1, 2, ..., m

> Xij less or iqual to Yj for all i, j

> sum{from j = 1 to n} of Yj = p, where p is a constant

> sum{from i = 1 to m} of Xij less or equal to k * Yij  , j = 1,2,..., n

> Yj belongs to {0,1} for all j
> Xij belongs to {0,1} for all i, j

> could some one help me out, bc I have a big problem.

> Im working on my Thesis and I need to solve many transportations
> problems and Im getting wrong results bc im comparing with CPLEX that
> one of my teachers work with.

You can try writing your model in the GNU MathProg modeling language
(a subset of AMPL) and then use the solver glpsol to solve the model
with different data.

See some MathProg examples in subdirectory 'examples' included in the
glpk distribution, in particular, examples/transp.mod.