Hi minimizers out there,
 The function praxis for
 the minimization of a function in several variables is coded in C. It
 runs currently under Unix and under MSDOS, and will probably run on
 any machine with a C-Compiler. A Pascal version of the program is
 also available.
 The routine originally appeared in a book by R.P. Brent on
 minimization. I translated his algol-something program to
 Turbo-Pascal, some years ago. Now I have converted the same thing to
 C, for various reasons. First it runs twice as fast on an IBMPC,
 second I forgot how to write programs in Pascal.
 The algorithm that's used was first given by Powell (1962) and is
 referenced in the recent literature as the fastest one without
 derivates. Brent fixed some minor problems and reduced the number of
 function calls by including some other overhead, like doing a
 singular value decomposition of the direction matrix every N
 iterations (N is the number of parameters). Thus this routine is
 particulary useful, when the evaluation of the object function is
 very time consuming. I used it extensively for some of my work,
 where this condition was true. 
 The following files are included in this package:

  readme	this file
  machine.h	include file which sets the value for the machine
		precision, and the maximum number of parameters
  praxis.c	the minimization routine
  minfit.c	the routine, that is used for the singular value
		decomposition
  rosen.c	one of the test functions from the literature
  tp.c		an example main program
  makefile	makefile for Unix, creates tp
  makefile.msc	makefile for MSDOS
  tp.p		sample main program for Unix pascal
  praxis.i	include file for Unix pascal
  tp.pas	sample main program for TURBO-Pascal
  praxis.inc	include file for TURBO-Pascal

Usage of praxis is very simple and is explained in detail in a comment
inside the program. If you are interested in updates or have any
suggestions, mail me a note. I will put you on a mailing list for
updates and/or similiar programs.

		
Karl Gegenfurtner

arpa:	karl@hipl.psych.nyu.edu
uucp:	...{seismo|ihnp4|allegra}!cmcl2!xp!hipl!karl
usps:	Department of Psychology, NYU
	6 Washington Place, 8th fl.
	New York, NY 10003