Simplex Controls

class ecyglpki.SimplexControls

The simplex solver control parameter object

>>> r = SimplexControls()

it_lim

Iteration limit, an int

>>> r.it_lim  # the GLPK default
2147483647
>>> r.it_lim = 10
>>> r.it_lim
10

meth

The simplex method, a str

The possible values are

• 'primal': two-phase primal simplex
• 'dual': two-phase dual simplex
• 'dual_fail_primal': two-phase dual simplex and, if it fails, switch to primal simplex

>>> r.meth  # the GLPK default
'primal'
>>> r.meth = 'dual_fail_primal'
>>> r.meth
'dual_fail_primal'

msg_lev

The message level, a str

The possible values are

• 'no': no output
• 'warnerror': warnings and errors only
• 'normal': normal output
• 'full': normal output and informational messages

>>> r.msg_lev  # the GLPK default
'full'
>>> r.msg_lev = 'no'
>>> r.msg_lev
'no'

obj_ll

Lower limit of the objective function, a Real number

(Used only if meth is 'dual'.)

>>> r.obj_ll  # the GLPK default
-1.7976931348623157e+308
>>> r.obj_ll = -1234.0
>>> r.obj_ll
-1234.0

obj_ul

Upper limit of the objective function, a Real number

(Used only if meth is 'dual'.)

>>> r.obj_ul  # the GLPK default
1.7976931348623157e+308
>>> r.obj_ul = 123.4
>>> r.obj_ul
123.4

out_dly

Output delay [ms] of solution process information, an int

>>> r.out_dly  # the GLPK default
0
>>> r.out_dly = 25
>>> r.out_dly
25

out_frq

Output frequency [iterations] of informational messages, an int

>>> r.out_frq  # the GLPK default
500
>>> r.out_frq = 50
>>> r.out_frq
50

presolve

Whether to use the LP presolver, a bool

>>> r.presolve  # the GLPK default
False
>>> r.presolve = True
>>> r.presolve
True

pricing

The pricing technique, a str

The possible values are

• 'Dantzig': standard ‘textbook’
• 'steepest': projected steepest edge

>>> r.pricing  # the GLPK default
'steepest'
>>> r.pricing = 'Dantzig'
>>> r.pricing
'Dantzig'

r_test

The ratio test technique, a str

The possible values are

• 'standard': standard ‘textbook’
• 'Harris': Harris’s two-pass ratio test

>>> r.r_test  # the GLPK default
'Harris'
>>> r.r_test = 'standard'
>>> r.r_test
'standard'

tm_lim

Time limit [ms], an int

>>> r.tm_lim  # the GLPK default
2147483647
>>> r.tm_lim = 1e7
>>> r.tm_lim
10000000

tol_bnd

Tolerance to check if the solution is primal feasible, a Real number

>>> r.tol_bnd  # the GLPK default
1e-07
>>> r.tol_bnd = 0.2
>>> r.tol_bnd
0.2

tol_dj

Tolerance to check if the solution is dual feasible, a Real number

>>> r.tol_dj  # the GLPK default
1e-07
>>> r.tol_dj = 0.01
>>> r.tol_dj
0.01

tol_piv

Tolerance to choose eligble pivotal elements, a Real number

>>> r.tol_piv  # the GLPK default
1e-10
>>> r.tol_piv = 1e-3
>>> r.tol_piv
0.001