Re: How to write this specific constraint in AIMMS?

137 views
Skip to first unread message

Guido Diepen

unread,
May 19, 2013, 11:08:14 AM5/19/13
to ai...@googlegroups.com
Hi,

please see my post http://blog.aimms.com/2011/11/generate-indexed-constraint-except-for-certain-elements/ on the AIMMS blog for more information about this. You can achieve this with domain conditions.

Guido Diepen
AIMMS Specialist

On Sunday, May 19, 2013 4:55:35 PM UTC+2, marcop...@gmx.de wrote:

Hey,

i am kinda new to AIMMS and have trouble with following expression. Maybe someone could help me with that and tell me how I can implement this in AIMMS (v3.13).

sum[j,(j<>'0')   Xojt = 1  for all t       whereby 0 is the starting point for index i, which is defined in a set 1 with indizes i, j, p.  Any ideas how i can set the i=0 in the constraint and also say that j <> 0 ?


Another constraint is the opposite:

sum[i,(i<>'0')   Xiot = 1  for all t  whereby 0 is the ending point for index j, which is defined in a set 1 with indizes i, j, p


Thanks in advance for your help in how to implement this.  Another questions would be, how to insert the Big M impression as a paramter?

marcop...@gmx.de

unread,
May 19, 2013, 11:26:01 AM5/19/13
to ai...@googlegroups.com
Hi Guido,

thnaks for your quick answer, but this post of yours doesn´t help me i guess. I dont see the link between this problem and that which is stated there?

In order to formulate my problem in AIMMS, i uploaded i screenshoot of my AIMMS Formulation (see below):
NB-Formulation.JPG

Guido Diepen

unread,
May 21, 2013, 7:38:40 AM5/21/13
to ai...@googlegroups.com
Hi Marco,

the post describes the domain condition for the index domain. However, you can use the same concept of domain conditions in the sum statement:

sum( i | i <> j and ord(i) > 1 ,   x(i,j,t) )

Note that you cannot use , to use multiple terms in an expression, you will have to use the and operator.

Guido Diepen
AIMMS Specialist
Reply all
Reply to author
Forward
0 new messages