The following algorithm control parameters are accessible via the dictionary solvers.options. By default the dictionary is empty and the default values of the parameters are used.

One can change the parameters in the default solvers by adding entries with the following key values.

'show_progress'

True or False; turns the output to the screen on or off (default: True).

'maxiters'

maximum number of iterations (default: 100).

'abstol'

absolute accuracy (default: 1e-7).

'reltol'

relative accuracy (default: 1e-6).

'feastol'

tolerance for feasibility conditions (default: 1e-7).

'refinement'

number of iterative refinement steps when solving KKT equations (default: 1).

For example the command

>>> from cvxopt import solvers
>>> solvers.options['show_progress'] = False

turns off the screen output during calls to the solvers. The tolerances abstol, reltol and feastol have the following meaning in nlcp().

cpl() returns with status 'optimal' if

where x_0 is the point returned by F(), and

where

The functions cp(), qp(), and gp() call cpl() and hence use the same stopping criteria (with x_0=0 for qp() and gp()).

The MOSEK interior-point algorithm parameters are set to their default values. They can be modified by adding an entry solvers.options['MOSEK']. This entry is a dictionary with MOSEK parameter/value pairs, with the parameter names imported from pymosek. For details see Section 14.1.3 of the MOSEK Python API Manual.

For example the commands

>>> from cvxopt import solvers 
>>> import pymosek
>>> solvers.options['MOSEK'] = {pymosek.iparam.log: 0}

turn off the screen output during calls of qp() with the 'mosek' option.