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One might wish to sum items as follows
r=sum(I,y[I]);
r=sum((I,j),y(i)+w(j));
eq5[I].. zz[I]=e=sum[j,zz[i-1]+zq[j]];
Here the sum is computed over all of
the elements in I for the first equation
the elements in I and j for the second equation
the elements in j for the third equation
Notes:
| • | The general syntax is sum(settovary,expression) where |
| — | The settovary is the name of the sets or sets that will be varied |
| — | When more than one set is to be varied they are enclosed in parentheses – sum((i,j),x(i,j)). |
| — | Expression is a generally a function of the set in the sum |
| — | A ( occurs just after the word sum and matches with a ) at the end of the sum. |
| • | In replacement statements parameters, and scalars can freely appear. Variables and equations can only be present if attributes of them are being addressed. |
| • | In model equation specification statements parameters, scalars and variables can freely appear. |
| • | The expression after the comma is fully computed and then applied to the sum as if the term were in parentheses. |
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