[AMPL 2113] matrices

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[AMPL 2113] matrices

mah-5

Matrices problem can be solved by using these two commands: ‘for all’ and ‘sum’ in Mosel language like:

For all(j in NG) sum(l in NL) A(j,l)*pf(l)=(PG(j)+dpgplus(j)-dpgminus(j)-P_DEMAND(j))

There are lots of errors when I use only sum (l in NL) A(i.l)*pf(l) about unknown 'i' in AMPL.

 Which chapter of AMPL book does focus on matrices? In which chapter can I find an example of matrices



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[AMPL 2114] Re: matrices

Robert Fourer-2

A matrix in AMPL is an entity indexed over two sets, or more generally over a set of ordered pairs.  Chapter 6 of the AMPL book discusses indexing of this sort.  For the example you give, you could write in AMPL:

 

   subj to DemandConstraint {j in NG}:

      sum {l in NL} A[j,l] * pf[l]

         = PG[j] + dpgplus[j] - dpgminus[j] - P_DEMAND[j];

 

Of course before specifying this constraint you would have to define the entities that appear in it.  To define the "matrix" A you could specify:

 

   param A {NG,NL};

 

Bob Fourer

[hidden email]

 

 


From: [hidden email] [mailto:[hidden email]]

On Behalf Of mahbube zeraatzade
Sent: Friday, December 05, 2008 3:52 PM
To: [hidden email]
Subject: [AMPL 2113] matrices

 

Matrices problem can be solved by using these two commands: ‘for all’ and ‘sum’ in Mosel language like:

For all(j in NG) sum(l in NL) A(j,l)*pf(l)=(PG(j)+dpgplus(j)-dpgminus(j)-P_DEMAND(j))

There are lots of errors when I use only sum (l in NL) A(i.l)*pf(l) about unknown 'i' in AMPL.

 

Which chapter of AMPL book does focus on matrices? In which chapter can I find an example of matrices

 


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