`scipy.optimize._linprog_simplex:_apply_pivot`

source: /scipy/optimize/_linprog_simplex.py :169

Signature

def _apply_pivot ( T , basis , pivrow , pivcol , tol = 1e-09 )

Summary

Pivot the simplex tableau inplace on the element given by (pivrow, pivol). The entering variable corresponds to the column given by pivcol forcing the variable basis[pivrow] to leave the basis.

Parameters

T : 2-D array

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.

basis : 1-D array

An array of the indices of the basic variables, such that basis[i] contains the column corresponding to the basic variable for row i. Basis is modified in place by _apply_pivot.

pivrow : int

Row index of the pivot.

pivcol : int

Column index of the pivot.

Aliases

scipy.optimize._linprog_simplex._apply_pivot