not equal tupels

[Nikou]

Hello

I declare

SET i / a1 a2 a3 / ;
SET j / b1 b2 b3 / ;
SET k / 1 2 3 / ;

alias i, i1 ;
alias j, j1 ;
alias k, k1 ;

Eq(i,j,k,i1,j1,k1)...

How can I make sure that the combination (i1,j1,k1) doesn't get the same as (i,j,k) ?

Eq(i,j,k,i1,j1,k1)$( (ord(i)<>ord(i1)) and (ord(j)<>ord(j1)) and (ord(k)<>ord(k1))) ... is not correct,

because it doesn't allow Eq(a1,b1,1,a1,b1,2), which should be allowed

Forbiden should be something like Eq(a1,b1,1,a1,b1,1) or Eq(a2,b1,1,a2,b1,1) ....


What is the correct way to write this?

Perhaps

Eq(i,j,k,i1,j1,k1)$( (ord(i)<>ord(i1)) and (ord(j)<>ord(j1)) and (ord(k)<>ord(k1))) ... ... ?

Somehow I messing this up!

[petros.p]

Hi,

try this:

Code: Select all

eq(i,j,k,ii,jj,kk)$(ord(i) <> ord(ii) and ord(j) <> ord(jj) and ord(k) <> ord(kk))..

Best,
Petros

[Nikou]

Petros

I am sorry, my question is not written down correctly. It is not about the syntax, it is about the result.

I just corrected the question.

[petros.p]

Hi nikou,

Now I see, but I think that you could get the result you want if you just replace AND with OR.

Best,
Petros

[dirkse]

Nikou,

I find it helpful to use a tuple set so I can see what is in it. That's easier than looking at equations, and you can use the tuple set to define the subset of equations you generate. Like this:

Code: Select all

sets
  i / i1, i2 /
  j / j1, j2 /
  ;
alias (i, i1), (j, j1);
set tuples(i,j,i1,j1);
tuples(i,j,i1,j1)$[not (sameas(i,i1) and sameas(j,j1))] = yes;
equation equ(i,j,i1,j1);
* equ(tuples(i,j,i1,j1)) .. blah blah;

I assume you will dump all the data to GDX and use GAMS Studio or GAMSIDE to look at the contents of the tuples set.

-Steve