Sage Reference Manual: Numerical Optimization - Mirrors

Sage Reference Manual: Numerical Optimization, Release 6.1.1
EXAMPLE:
sage: from sage.numerical.backends.generic_backend import get_solver
sage: p = get_solver(solver = "GLPK")
sage: p.add_variables(5)
4
sage: p.add_linear_constraint(zip(range(5), range(5)), 2, 2)
sage: p.row(0)
([4, 3, 2, 1], [4.0, 3.0, 2.0, 1.0])
sage: p.row_bounds(0)
(2.0, 2.0)
row_bounds(index)
Return the bounds of a specific constraint.
INPUT:
•index (integer) – the constraint’s id.
OUTPUT:
A pair (lower_bound, upper_bound). Each of them can be set to None if the constraint is not
bounded in the corresponding direction, and is a real value otherwise.
EXAMPLE:
sage: from sage.numerical.backends.generic_backend import get_solver
sage: p = get_solver(solver = "GLPK")
sage: p.add_variables(5)
4
sage: p.add_linear_constraint(zip(range(5), range(5)), 2, 2)
sage: p.row(0)
([4, 3, 2, 1], [4.0, 3.0, 2.0, 1.0])
sage: p.row_bounds(0)
(2.0, 2.0)
row_name(index)
Return the index th row name
INPUT:
•index (integer) – the row’s id
EXAMPLE:
sage: from sage.numerical.backends.generic_backend import get_solver
sage: p = get_solver(solver = "GLPK")
sage: p.add_linear_constraints(1, 2, None, names=[’Empty constraint 1’])
sage: p.row_name(0)
’Empty constraint 1’
set_objective(coeff, d=0.0)
Set the objective function.
INPUT:
•coeff - a list of real values, whose ith element is the coefficient of the ith variable in the objective
function.
•d (double) – the constant term in the linear function (set to 0 by default)
EXAMPLE:
72 Chapter 5. LP Solver backends