1 Limited-memory BFGS code by Ciyou Zhu, Richard Byrd, Peihuang Lu, and
2 Jorge Nocedal, which can be found (in various translations) at various
5 http://www.alglib.net/optimization/lbfgsb.php
6 http://plato.asu.edu/ftp/other_software/toms778_f90.tar.gz
8 Unfortunately, since it was published in ACM TOMS, it seems to be
9 under the restrictive (semi-free) ACM copyright conditions. This was
10 confirmed in a private email from the author, Prof. Nocedal.
12 Therefore, we no longer use this code in NLopt.
14 Fortunately, Prof. Luksan's PLIN.FOR code (see the luksan/ directory)
15 is an independent implementation of the same algorithm, and is licensed
18 UPDATE: Nocedal has apparently gotten permission from ACM to distribute
19 his L-BFGS code under the terms of the GPL:
21 http://www.eecs.northwestern.edu/~nocedal/lbfgsb.html
23 Therefore, it seems possible to re-incorporate this code into
24 NLopt, and I will look into this for a future release.
25 However, that will put NLopt under the terms of the GPL, so I
26 will need to keep it as an optional package.