Version gsl-1.7: (1) directional_minimize.c in the minimize routine:
double iter = 0; should be changed to int iter = 0; Some of the type double comparisons made later in the routine are compared to 0 rather than 0. These changes should speed up the routine (since casts are avoided). I imagine the effect is minute, and possibly not even measurable so that is why I classify these issues as merely a stylistic concern. (2) vector_bfgs.c: The method is incorrectly classified in a few places as a conjugate gradient method rather than the appropriate classification which is a quasi-Newton method. This incorrect classificiation could cause some misunderstandings for people unfamiliar with minimization methods. Here are my suggested changes: (a) In one comment conjugate gradient method ==> quasi-Newton method (b) In two output messages: conjugate direction ==> direction (3) This same confusion also occurs in http://www.network-theory.co.uk/docs/gslref/gsl-ref_467.html when the method is described as follows: "This is the vector Broyden-Fletcher-Goldfarb-Shanno (BFGS) conjugate gradient algorithm. It is a quasi-Newton method which builds up an approximation to the second derivatives of the function f using the difference between successive gradient vectors." I think "conjugate gradient" should be dropped from that first sentence. These are all extremely minor nit-picks, but nevertheless, it would be nice to get these issues cleaned up. Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the Yorick front-end to PLplot (yplot.sf.net); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ _______________________________________________ Bug-gsl mailing list [email protected] http://lists.gnu.org/mailman/listinfo/bug-gsl
