Using Sum for defining a set

Problems with syntax of GAMS
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argon
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Using Sum for defining a set

Post by argon »

Hi,

I'm a new user and I was trying to practice with the gasnet.gms : Optimal Design of a Gas Transmission Network from GAMS library. I have difficulty understanding the following equations:

cj(j,ii) = sum(i, jii(j,ii,i));
qi(ii,i) = sum(j, jii(j,ii,i));
ji(j,i) = sum(ii, jii(j,ii,i));
is(ii) = sum(j, cj (j,ii));

To show the code from the begining:

Code: Select all

 $eolCom //

Set
   ii    'all pipe segments' / s0*s11 /
   i(ii) 'pipe segments'     / s1*s11 /
   i1(i) 'segments one'      / s1*s3  /
   i2(i) 'segments two'      / s4*s7  /
   i3(i) 'segments three'    / s8*s11 /
   j     'compressors'       / c1*c10 /
   jii(j,ii,i) 'connections'
               / c1.s0.s1, c2.s1.s2, c3.s2.s3, c4.s3.(s4,s8), c5.s4.s5
                 c6.s5.s6, c7.s6.s7, c8.s8.s9, c9.s9.s10,     c10.s10.s11 /
   qi(ii,i) 'pipeline flow mapping'
   cj(j,ii) 'compressor inflow mapping'
   ji(j,ii) 'compressor pipeline flow mapping'
   is(ii)   'all segments less terminal segments';

cj(j,ii) = sum(i,  jii(j,ii,i));
qi(ii,i) = sum(j,  jii(j,ii,i));
ji(j,i)  = sum(ii, jii(j,ii,i));
is(ii)   = sum(j,  cj (j,ii));
I could not find how this sum works in the documentations.
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