[Help-glpk] confusion on constraints

[dtucker]

How does one attempt to add a constraint
which does not involve every structural variable (i.e. x[m+1]...x[m+n])
using lpx_load_matrix?  It would seem that if I had three structural
variables (x1, x2, x3) and a constraint of the form x1 + x2 = 4, that I
would have the following

ia[1] = 1, ja[1] = 1, ar[1] = 1.0;
ia[2] = 1, ja[2] = 2, ar[2] = 1.0;
ia[3] = 1, ja[3] = 3, ar[3] = 0.0;

but, I receive the following run-time
error if I attempt to do this:

lpx_load_matrix: ar[1] = 0; zero element
not allowed


Don

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