Interior-point method routines

Problem.interior(IPointControls controls)

Solve LP problem with the interior-point method

Problem.ipt_status()

Retrieve status of interior-point solution

Problem.ipt_obj_val()

Retrieve objective value (interior point)

Returns:the objective value of the interior point solution
Return type:float
Problem.ipt_row_prim(row)

Retrieve row primal value (interior point)

Parameters:row (int or str) – the index or name of the row
Returns:the solution value
Return type:float
Problem.ipt_row_dual(row)

Retrieve row dual value (interior point)

Parameters:row (int or str) – the index or name of the row
Returns:the solution value
Return type:float
Problem.ipt_col_prim(col)

Retrieve column primal value (interior point)

Parameters:col (int or str) – the index or name of the column
Returns:the solution value
Return type:float
Problem.ipt_col_dual(col)

Retrieve column dual value (interior point)

Parameters:col (int or str) – the index or name of the column
Returns:the solution value
Return type:float

Interior-point controls

class ecyglpki.IPointControls

The interior point solver control parameter object

>>> r = IPointControls()
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'
ord_alg

The ordering algorithm used prior to Cholesky factorization, a str

The possible values are

  • 'orig': normal (original)
  • 'qmd': quotient minimum degree
  • 'amd': approximate minimum degree
  • 'symamd': approximate minimum degree for symmetric matrices
>>> r.ord_alg  # the GLPK default
'amd'
>>> r.ord_alg = 'qmd'
>>> r.ord_alg
'qmd'