[FlopCpp] wrote first flopcpp model. have a lot of questions
Mario Rappi
marappi at wichita.edu
Sat Nov 28 20:46:59 EST 2009
First I include the model, then the output, and at the end the questions:
*****model************************
// $Id$
#include "flopc.hpp"
using namespace flopc;
#include <OsiClpSolverInterface.hpp>
int main() {
MP_model &model = MP_model::getDefaultModel();
model.setSolver(new OsiClpSolverInterface);
model.verbose();
enum {storeA, storeB, storeC, storeD, numS};
enum {Input1, Input2, numI};
enum {Output1, numO};
MP_set S(numS); // Stores
MP_set I(numI); // Inputs
MP_set O(numO); // Outputs
MP_subset<2> Input(S,I);
Input.insert(S,I);
Input.display("Input");
MP_subset<2> Output(S,O);
Output.insert(S,O);
Output.display("Output");
//this will be easier with an array??
MP_data InputVal(Input);
InputVal(storeA,Input1)=1; InputVal(storeA,Input2)=3;
InputVal(storeB,Input1)=3; InputVal(storeB,Input2)=3;
InputVal(storeC,Input1)=4; InputVal(storeC,Input2)=2;
InputVal(storeD,Input1)=3; InputVal(storeD,Input2)=1;
MP_data OutputVal(Output);
OutputVal(storeA,Output1)=1;
OutputVal(storeB,Output1)=1.5;
OutputVal(storeC,Output1)=2;
OutputVal(storeD,Output1)=1;
MP_variable x(I), y(O);
x.lowerLimit(I)=0;
y.lowerLimit(O)=0;
MP_constraint efficiency(S);
efficiency(S) = sum(I, InputVal(S, I) * x(I)) <= sum(O, OutputVal(S, O)
* y(O));
minimize( (sum(O, OutputVal(storeB, O) * y(O))) - (sum(I,
InputVal(storeB, I) * x(I))));
efficiency.display("constraints");
x.display("x");
y.display("y");
cout<<"Test dea passed."<<endl;
}
*****model end************************
*****output************************
Input
Output
FlopCpp: Constraint
0 1 0 0
1 1 0 0
2 1 0 0
3 1 0 0
0 2 0 0
1 2 0 0
2 2 0 0
3 2 0 0
0 0 -0 0
1 0 -0 0
2 0 -0 0
3 0 -0 0
FlopCpp: Number of constraint blocks: 1
FlopCpp: Number of individual constraints: 4
FlopCpp: Number of variable blocks: 2
FlopCpp: Number of individual variables: 3
FlopCpp: Number of non-zeroes (including rhs): 12
Objective
-1 0 0
-1 1 -0
-1 2 -0
FlopCpp: Generation time: -2.64274e-19
Clp0000I Optimal - objective value 0
Clp0032I Optimal objective 0 - 0 iterations time 0.002
FlopCpp: Optimal obj. value = 0
FlopCpp: Solver(m, n, nz) = 4 3 0
constraints
0 -1.79769e+308 0 0 -0
1 -1.79769e+308 0 0 -0
2 -1.79769e+308 0 0 -0
3 -1.79769e+308 0 0 -0
x
0 0
1 0
y
0 0
Test dea passed.
*****output end************************
*****Questions:******************
I would like to define a set A that includes all members of O and I and then
derive O and I from A.
This is what I am thinking in GAMS terms:
A / Input1, Input2, Output1 /
O(A) / Input1, Input2 /
I(A) / Output1 /
Is this possible?. I thought it would allow me to write the model more
easily (but may be not)
*******************
I tried to display the constraints but I didn't get what I was expecting
(the actual mathematical expression). Is it possible to see the constraints
in any other way?
*******************
When I compile I get the following two warnings. Should I be concerned? How
do I fix them?
c:\program files\coin-flopcpp\flopcpp\src\mp_set.hpp(259) : warning C4267:
'return' : conversion from 'size_t' to 'int', possible loss of data
c:\program files\coin-flopcpp\flopcpp\src\mp_set.hpp(258) : while
compiling class template member function 'int
flopc::MP_subset<nbr>::size(void) const'
with
[
nbr=2
]
c:\program files\coin-flopcpp\flopcpp\examples\dea.cpp(21) : see
reference to class template instantiation 'flopc::MP_subset<nbr>' being
compiled
with
[
nbr=2
]
c:\program files\coin-flopcpp\flopcpp\src\mp_set.hpp(243) : warning C4267:
'initializing' : conversion from 'size_t' to 'const int', possible loss of
data
c:\program files\coin-flopcpp\flopcpp\src\mp_set.hpp(232) : while
compiling class template member function 'void
flopc::MP_subset<nbr>::insert(const std::vector<_Ty> &)'
with
[
nbr=2,
_Ty=int
]
*******************
The objective function that I really want to use is
maximize( (sum(O, OutputVal(storeB, O) * y(O))) / (sum(I, InputVal(storeB,
I) * x(I))));
But it doesn't compile, I get this error:
c:\program files\coin-flopcpp\flopcpp\examples\dea.cpp(51) : error C2678:
binary '/' : no operator found which takes a left-hand operand of type
'flopc::MP_expression' (or there is no acceptable conversion)
c:\program files\coin-flopcpp\flopcpp\src\mp_constant.hpp(141):
could be 'flopc::Constant flopc::operator /(const flopc::Constant &,const
flopc::Constant &)'
c:\program
files\coin-flopcpp\coinutils\src\coinpackedvector.hpp(483): or
'CoinPackedVector operator /(const CoinPackedVectorBase &,const
CoinPackedVectorBase &)'
c:\program
files\coin-flopcpp\coinutils\src\coinpackedvector.hpp(583): or
'CoinPackedVector operator /(const CoinPackedVectorBase &,double)'
c:\program
files\coin-flopcpp\coinutils\src\coinpackedvector.hpp(625): or
'CoinPackedVector operator /(double,const CoinPackedVectorBase &)'
while trying to match the argument list '(flopc::MP_expression,
flopc::MP_expression)'
I am using MSVCPP, I read of some problems specific to VCPP so I tried the
same in Linux(I think it is build-essential in Ubuntu) but I get the same
errors.
How can I fix this problem with the division operation?
*******************
Is my formulation of the objective function OK in how I sum only for storeB
or do I have to use such_that or any other type of control?
How do I display the objective function?
*******************
What are these numbers in the output?
constraints
0 -1.79769e+308 0 0 -0
1 -1.79769e+308 0 0 -0
2 -1.79769e+308 0 0 -0
3 -1.79769e+308 0 0 -0
My four constraints are supposed to have only three terms (two on the left
and one on the right)
********************
What is this?
Objective
-1 0 0
-1 1 -0
-1 2 -0
********************
If it helps at all: the model is a simple DEA formulation (primal).
I understand some of my questions may be more C++ than flopcpp questions but
I can't tell.
I will appreciate help on any of these questions and on any other comments
you may have on the model formulation.
Thanks in advance.
Mario
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