This directory has the files for the algorithm 
used to compute the step in a trust region method.
Further information can be found in the paper

J. J. Mor\'e and D. C. Sorensen,
Computing a trust region step,
SIAM J. Sci. Statist. Comput. 4 (1983), 553-572.

Site web ell_lib: https://tcg.mae.cornell.edu/ELL_LIB/