Originally posted by: csfab

Dear, all right.

My name is Fernando, and I live in Brazil, and I am just getting into the use of CPLEX, I, along with my students, are doing a work based on the traveling salesman with 1500 points.

We have an array of distances of 1500x1500 and we want to sort out a coordinate point (row, column) and calculate the shortest distance to that point given a starting point.

We're not getting the rand function to work.

Thank you.

#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

a few starting points for TSP : https://www.ibm.com/developerworks/community/forums/html/topic?id=f58daf79-f752-48e4-8f25-54b2f6f71b40&ps=25

some how to in OPL https://www.linkedin.com/pulse/how-opl-alex-fleischer/

plus https://www.linkedin.com/pulse/o-que-%C3%A9-otimiza%C3%A7%C3%A3o-e-como-isso-pode-ajud%C3%A1-lo-fazer-mais-fleischer/

For rand, you have an example in the OPL documentation:

int r1[i in 1..10]=rand(10);
int r2[i in 1..10]=rand();

execute
{
 writeln("int r1[1..10]=rand(10) gives ",r1);  
 writeln("int r2[1..10]=rand() gives ",r2);

}

regards

#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: csfab

Hello, Alex, how are you?

So, I had already seen the manual but could not get it to work:

Here's the template I'm working on:

 

 

//Parâmetros

 

1) I want to sort a distance from the distance matrix

 

 

float destino[cidades][cidades] = rand(distancias); 

 

 

 

#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

what about

//Parâmetros
int n = 100;
range cidades = 1..n;
float x[cidades];
float y[cidades];
float distancias[cidades][cidades];

 

//Pré-processamento
 
execute DADOS{
function calcdistancia(cidadea,cidadeb){
return Opl.sqrt(Opl.pow(x[i]-x[j], 2)+ Opl.pow(y[i]-y[j], 2));
 
}
 
 
for (var c in cidades){
x[c]=Opl.rand(2000);
y[c]=Opl.rand(2000);
writeln ("cidade" + ' '+c+": ("+x[c]+','+y[c]+")");}
 
for (var i in cidades)
for (var j in cidades)
if (i!=j){
distancias[i][j]=calcdistancia(i,j);
if (j>i){
writeln ("A distância entre a cidade"+' '+i+' '+"e a cidade"+ ' ',j+ ' '+ "é de "+' '+distancias[i][j]+ ' '+"km");
}
}
}

 

float destino[c1 in cidades][c2 in cidades] = rand(ftoi(ceil(distancias[c1][c2])));

 

 

 

 
//Variáveis de decisão
dvar boolean rota[cidades][cidades];
dvar float+ u[cidades];
 
//Expressões
dexpr float caminho = sum(i in cidades, j in cidades: i!=j) distancias[i][j]*rota[i][j];
 
//Função objetivo
minimize
  caminho;
 
//Restrições
 
subject to{
 
flowing:
forall (j in cidades)
  sum(i in cidades: i!=j) rota[i][j]==1;
 
flowout:
forall (i in cidades)
  sum(j in cidades: i!=j) rota[i][j]==1;
 
ESubrotas:
forall (i in cidades, j in cidades: i>1 && j>1 && i!=j)
  u[i]-u[j] + n*rota[i][j] <= n-1;
 
 
}

?

 

regards

 

https://www.linkedin.com/pulse/o-que-%C3%A9-otimiza%C3%A7%C3%A3o-e-como-isso-pode-ajud%C3%A1-lo-fazer-mais-fleischer/

#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: csfab

It's a TSP template, which I'm adapting.

In which I have an array of 1400 rows and 1400 columns.

Within this matrix I have a coordinate that is the origin and I want to get to another point that is the destination.

Then the model will calculate the smallest path from source to destination.

Maybe we'll use another model.

Thank you.

#DecisionOptimization
#OPLusingCPLEXOptimizer