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I am struggling again NMinimize.

This is my problem:

I am creating a model by using goal programming, my problem now is given a list of list i.e a matrix defined in this way

S = {{5, 2, 7, 9}, {1, 2, 3, 4}, {3, 1, 2, 4}}

extract from the first list {5,2,7,9} a number by passing a variable in extract method.

I mean, this is my model:

NMinimize [{

n1+p1, (this is my objective function)

x1j == 2 (Now i am using a stupid number but this will be modified)

Ʃ Extract[Extract[S,1],x1j]+n1-p1 == 10, (The summation start from j=1 to 2)

n1>= 0,

p1>=0

},{x1j,n1,p1}]

In this case, on my side the result should be x11 = 5, x12 = 5, n1=0, p1=0, but unfortunately this not happen.

This error is launched:

Extract::psl: Position specification Subscript[x, 1,1] in Extract[{5,2,7,9},Subscript[x, 1,1]] is not an integer or a list of integers. >>

NMinimize::bcons: The constraints are not valid. >>

Someone can help me?

Thanks a lot!

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# Mathematica, NMinimize extract data from list

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