Originally posted by: gregman

Dear Cplex-Community,

I am currently struggling with the following problem:

given a set p = {1,2}

given a set of ranges W_i

Since W_i is dependent on p, W_2 is supposed to be 1..6, W_1=3..5 and both are dependent on p, respectively. It is not possible to create 2 separate simple ranges. 

-Is it possible to create a set of ranges W_i in Cplex with different starting and ending points?

-Furthermore, could you give me the syntax for a max() formula inside a sum?

Example: sum (a in 1..max(b,c) ).

Thanks a lot,

Greg

Hi,

a small example for you:

int rangemin[1..2]=[2,3];
int rangemax[1..2]=[4,5];

int b=4;
int c=5;

int d=sum (a in 1..maxl(b,c)) 1;

execute
{
writeln(rangemin,rangemax);

writeln(d);
}

which gives

[2 3] [4 5]
5

regards

Originally posted by: gregman

Hello Alex and the rest of you,

thanks a lot for your reply. Unfortunately, it does not solve my problem, maybe because I wasn't precise enough.

- What you proposed for my first problem are arrays but what I need are ranges:

range A1 = 1,2,3,4,5,6,7 which is equal to range A1 = 1..7

range A2 = 2,3,4,5,6 (or 2..6)

range A3 = 3,4,5,6,7

Is it possible to create only one multi-dimensional range A_i = {A1,A2,A3} that obtains all given ranges instead of creating i separate ranges so that I can use e.g. forall (i in I, j in A(i) )

- For the max-problem I need a syntax that allows me to code the following part:

forall (i in I) sum (j in 1.. max(i,b)) ...

The max-function has to be directly integrated in the sum statement because it is dependent on the current state of the loop index i inside forall.

Is there a synthax for that?

Thank you very much.

Greg

Hi

int rangemin[1..2]=[2,3];
int rangemax[1..2]=[4,5];

{int} ranges[i in 1..2]=asSet(rangemin[i]..rangemax[i]);

int b=4;
int c=5;

int d=sum (a in 1..maxl(b,c)) 1;

range I=1..10;
dvar int x[I];
subject to
{
forall (i in I) sum (j in 1.. maxl(i,b)) x[j]<=i;
}

execute
{
writeln(ranges);

writeln(d);
}

Instead of arrays of ranges you may use array of sets.

Again, for the max, as written before you should use maxl

regards