_pivot_row(T, basis, pivcol, phase, tol=1e-09, bland=False)
A 2-D array representing the simplex tableau, T, corresponding to the linear programming problem. It should have the form:
[[A[0, 0], A[0, 1], ..., A[0, n_total], b[0]],
[A[1, 0], A[1, 1], ..., A[1, n_total], b[1]], . . . [A[m, 0], A[m, 1], ..., A[m, n_total], b[m]], [c[0], c[1], ..., c[n_total], 0]]
for a Phase 2 problem, or the form:
[[A[0, 0], A[0, 1], ..., A[0, n_total], b[0]],
[A[1, 0], A[1, 1], ..., A[1, n_total], b[1]], . . . [A[m, 0], A[m, 1], ..., A[m, n_total], b[m]], [c[0], c[1], ..., c[n_total], 0], [c'[0], c'[1], ..., c'[n_total], 0]]
for a Phase 1 problem (a Problem in which a basic feasible solution is sought prior to maximizing the actual objective. T
is modified in place by _solve_simplex
.
A list of the current basic variables.
The index of the pivot column.
The phase of the simplex algorithm (1 or 2).
Elements in the pivot column smaller than tol will not be considered for pivoting. Nominally this value is zero, but numerical issues cause a tolerance about zero to be necessary.
If True, use Bland's rule for selection of the row (if more than one row can be used, choose the one with the lowest variable index).
True if a suitable pivot row was found, otherwise False. A return of False indicates that the linear programming problem is unbounded.
The index of the row of the pivot element. If status is False, row will be returned as nan.
Given a linear programming simplex tableau, determine the row for the pivot operation.
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