# Admissible

### From Glossary

Generically means something that satisfies conditions. One example is the admissibility of
a direction of change of some parameter, such as a right-hand side of a
linear program (LP) from to ,
where is some scalar and is the direction of change. For a
positive value of , this might cause the LP to become infeasible,
no matter how small it is. In that case it is common to call
the direction vector *inadmissible*. For a perturbation to be
admissible in this context, it is required that the mathematical
program have a solution in some neighborhood of that direction. For
the example, is admissible if the (primal) LP is feasible for all
for some .

Admissibility need not be for directions of change in the
context of sensitivity analysis. The term is used elsewhere and
defined for the context in which it is used. For example, a
primal ascent algorithm could define a direction,
say , to be *admissible* if is
feasible and for all
for some .