Questions regarding SAS Sets.

[wutao9999]

In SAS OPTMODEL procedure, let's assume we have four string sets: products {pro1, pro2, pro3}, items {pro1, pro2, pro3}, fakeitem {pro1, pro3}, gooditem {pro1, gooda, goodb};

and one number, cost(products) = {3, 5, 2}.

Then apparently, we have sum{p in products} cost(p) = 10.

My question to you is that: Are the below three equations true as well?

sum{p in items} cost(p) = 10;

sum(p in fakeitem} cost(p) = 5;

sum(p in gooditem} cost(p) = 3.

Appreciate your answers, thank you very much.

[RobPratt · Accepted solution]

The first two equations are true.  The third equation requires cost['gooda'] and cost['goodb'] to be defined.  You could assign those costs to be 0, and then the third equation would be true.  Alternatively, you could modify the sum in the third equation in any of the following three ways:

sum{p in gooditem inter products} cost

sum{p in gooditem: p in products} cost

sum{p in gooditem} (if p in products then cost

)

Each of these approaches would yield 3.