The theory and implementation of an optimization algorithm code based
on the method of feasible directions are presented. Although the metho
d of feasible directions was developed during the 1960's, the present
implementation of the algorithm includes several modifications to impr
ove its robustness. In particular, the search direction is generated b
y solving a quadratic program which uses an interior method based on a
variation of Karmarkar's algorithm. The constraint thickness paramete
r is dynamically adjusted to yield usable-feasible directions. The the
ory is discussed with emphasis on the important and often overlooked r
ole played by the various parameters guiding the iterations within the
program. Also discussed is a robust approach for handling infeasible
starting points. The code was validated by solving a variety of struct
ural optimization test problems that have known solutions (obtained by
other optimization codes). A variety of problems from different infea
sible starting points has been solved successfully. It is observed tha
t this code is robust and accurate. Further research is required to im
prove its numerical efficiency while retaining its robustness.