[Wien] A feature of the new mixer

[Laurence Marks]

The new mixer has a "feature" which makes it behave relatively poorly
if you change parameters during a run (e.g. GMAX and probably RKMAX)
without deleting the previous history (case.broydX) files. Very
concisely, the old method would overwrite prior information with the
most recent, while the new one uses all the information in the
previous steps (that you specify in case.inm). If you change
parameters :DIS will probably get larger and the algorithm believes
that it has taken some bad steps so will slow down. Eventually the
steps with the pervious parameters will age out and the algorithm will
start behaving properly. There is no automatic cure for this (the
algorithm cannot read your mind, alas), so please delete the history
files if you change parameters.

N.B., I would be interested in feedback about how the algorithm is
behaving -- better hopefully.

-- 
Laurence Marks
Department of Materials Science and Engineering
MSE Rm 2036 Cook Hall
2220 N Campus Drive
Northwestern University
Evanston, IL 60208, USA
Tel: (847) 491-3996 Fax: (847) 491-7820
email: L-marks at northwestern dot edu
Web: www.numis.northwestern.edu
EMM2007 http://ns.crys.ras.ru/EMMM07/
Commission on Electron Diffraction of IUCR
www.numis.northwestern.edu/IUCR_CED