Bratio

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This option specifies what GAMS will do in forming an advanced basis as discussed in the Basis chapter.  This option is used by setting

 

Option Bratio=realnumber;

 

The value specified for this option causes a basis to be discarded if the number of basic variables is smaller than bratio times the number of equations.

Notes:

Setting bratio to 1 will always cause the basis to be discarded, which is sometimes needed with nonlinear problems as discussed in the NLP and Basis chapters.
Setting bratio to 0 forces GAMS to always try to construct a basis.
If bratio has been set to 0 and there was no previous solve, an "all slack" (sometimes called 'all logical') basis will be provided.
This option is not useful for MIP solvers.
The allowable values range from 0 to 1 with a default value of 0.25.