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Questions tagged [mathprog]

GNU MathProg is a modeling language intended for describing linear mathematical programming models. MathProg can also be referred to as GMPL

GNU MathProg is a high-level language for creating mathematical programming models. MathProg is specific to GLPK, but resembles a subset of AMPL. MathProg can also be referred to as GMPL (GNU Mathematical Programming Language), the two terms being interchangeable.

See https://en.wikibooks.org/wiki/GLPK/GMPL_%28MathProg%29

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How can I write an if condition for my variable in GLPK?

Here is my full problem: Information: *Max. total investment: $125 *Pay-off is the sum of the units bought x pay-off/unit *Cost per investment: Buy-in cost + cost/unit x number of units if you buy at least one unit *The cost is sum of the costs per…
Figen Güngör
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GLPK MathProg sets and groups

I hope this is obvious to someone. I have only had a vanilla use of GLPK/MathProg. I am having trouble figuring out the syntax in GNU MathProg (within GLPK) to do the following, for example: set PartsOfWeek; set WeekDays; data; set PartsOfWeek :=…
tipanverella
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Can't figure out how to resolve reduce/reduce conflict

I'm trying to create grammar for GNU MathProg language from glpk package https://www3.nd.edu/~jeff/mathprog/glpk-4.47/doc/gmpl.pdf Unfortunately grammar I've written so far is ambiguous. I don't know how to tell bison which branch of parsing tree…
Lisu
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Solving Steiner Tree with GLPK

I'm new at using the GPLK and I'm trying to solve the Steiner Tree problem through it. The mathematical formulation I'm using is this one: This is the piece of code I'm testing: # Number of terminal vertexes param p, integer; # Number of steiner…
user3369563
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Is it possible to convert a MathProg MIP file to a format recognised by SCIP?

I've been using GLPK to solve some mixed integer programming problems. Here's a sample input file in MathProg format: set REACTIONS; set REACTANTS; param Ys {i in REACTANTS, j in REACTIONS}; param Gamma {i in REACTANTS, j in REACTIONS}; param…
Kitserve
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Syntax error with Glpk: MathProg model processing error

This is my model: set linhas; set colunas; param c{j in colunas}; param A{i in linhas,j in colunas}; param b{i in linhas}; var x{j in colunas}>=0; minimize FO: sum{j in colunas} c[j]*x[j]; s.t. R{i in linhas}: sum{j in colunas} A[i,j] =…
Mar Oli
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Sum the binary variables in GLPK

I am new in GLPK. This is some of my code: set I := setof{(i,r,p,d) in T} i; var Y{I,I}, binary; s.t. c1{i in I, j in I}: sum{Y[i,j]} = 6; I want to have only six values in Y that are 1. Can anyone tell me how to do it in proper way? Because s.t.…
Gregorius Edwadr
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Issues with objective - GMPL

I'm trying to model an objective. It's a special case of assignment problem, where I want to minimize the workers needed for making all the jobs. So all jobs have to be done, but not all the workers have to do something. Constraints: s.t.…
thomas.kardos
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Reading CSV data into subscripted set

I would like to ask for your assistance with a problem I'm dealing for about a week. I have been looking everywhere for the solution. Official doc is not accurate enough and says nothing on that matter. The problem is the following: This is a part…
Marek
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Or Condition in Linear Programming with GLPSOL AMPL/MathProg

I want to write an optimization model which selects the lesser of the two tasks, depending upon some constraint. minimize obj: (doT1 * T1) + (doT2*T2) + (additional variables) Now, T1 and T2 represent duration of tasks, and doT1 represents flag to…
Asif Shiraz
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GLPK Mathprog group of sets

I'm trying to code a model that can solve the Multiple Choice Knapsack Problem (MCKP) as described in Knapsack Problems involving dimensions, demands and multiple choice constraints: generalization and transformations between formulations (Found…
Alex Ketay
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MathProg recursive function

I'm facing trouble in counting linked nodes in Mathprog while trying to solve a quite-big TSP problem: let's say I have set C := 0..645; # a set of nodes set A := {i in C, j in C: i!=j}; # a set of edges a distance function d(c1,c2) var…
Valentino Gregorutti
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Known values for variables in a linear program written in Mathprog

I have a linear program written in MathProg. My unknown binary variable is a two-dimensional array defined as: var x{i in V, l in L}, >=0, <=1; where V and L are sets of integers. The value of some variables, however, are known in advance and I…
Ari
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MathProg (AMPL) - Variable Array Sized by Another Variable

I am writing my first GNU MathProg (AMPL) program to find the minimum switch (vertex) count instances of a HyperX topology (graph) for a given radix, number of hosts, and bisection bandwidth. This is a simple first program because all of the…
bestephe
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Implementing a constraint based on previous variable's value in GNU Mathprog/AMPL

I have a binary program and one of my variables, x_it is defined on two sets, being I: Set of objects and T: Set of the weeks of the year, thus x_it is a binary variable standing for whether object i is assigned to something on week t. The…
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