Author: bugman
Date: Thu Jul 24 11:12:33 2014
New Revision: 24697
URL: http://svn.gna.org/viewcvs/relax?rev=24697&view=rev
Log:
Expanded the minimise.grid_zoom user function documentation.
A few sentences about the limitations of the algorithm have been added.
Modified:
branches/zooming_grid_search/user_functions/minimisation.py
Modified: branches/zooming_grid_search/user_functions/minimisation.py
URL:
http://svn.gna.org/viewcvs/relax/branches/zooming_grid_search/user_functions/minimisation.py?rev=24697&r1=24696&r2=24697&view=diff
==============================================================================
--- branches/zooming_grid_search/user_functions/minimisation.py (original)
+++ branches/zooming_grid_search/user_functions/minimisation.py Thu Jul 24
11:12:33 2014
@@ -394,10 +394,10 @@
uf.desc[-1].add_paragraph("The optimisation of a mathematical model normally
consists of two parts - a coarse grid search to find an initial set of
parameter values followed by the use of a high precision optimisation
algorithm to exactly find the local or global solution. But in certain
situations, for example where a parallelised grid search is advantageous, a
finer grid may be desired. The zooming grid search provides a more efficient
alternative to simply increasing the number of increments used in the initial
grid search. Note that in most situations, standard optimisation algorithms
will be by far computationally less expensive.")
uf.desc[-1].add_paragraph("The zooming grid search can be activated via this
user function. After setting the desired zoom level, the original grid
search user function should be called again. The zoom level is used to
decrease the total area of the grid search. The grid width for each
dimension of the parameter space will be divided by 2**zoom_level. So a
level of 1 will halve all dimensions, a level of 2 will quarter the widths, a
level of 3 will be an eighth of the widths, etc.")
uf.desc[-1].add_paragraph("The zooming algorithm proceeds as follows. The
new zoomed grid will be centred at the current parameter values. However if
the new grid is outside of the bounds of the original grid, the entire grid
will be translated so that it lies entirely within the original bounds. This
is to avoid grid points lying within undefined regions of the space. An
exception is when the zoom factor is negative, hence the new grid will be
larger than the original.")
-uf.desc[-1].add_paragraph("An example of using the zooming grid search is to
first perform a standard initial grid search, then set the zoom level to 1
and perform a second grid search. Continue for zoom levels 2, 3, etc. until
the desired fineness is obtained.")
+uf.desc[-1].add_paragraph("An example of using the zooming grid search is to
first perform a standard initial grid search, then set the zoom level to 1
and perform a second grid search. Continue for zoom levels 2, 3, etc. until
the desired fineness is obtained. Note that convergence is not guaranteed -
as the zoom level is increased to infinity, the parameter values do not
necessarily converge to the local minimum. Therefore performing standard
optimisation is recommended after completing a zooming grid search. ")
uf.backend = minimise.grid_zoom
uf.menu_text = "&grid_zoom"
uf.gui_icon = "oxygen.actions.zoom-in"
uf.wizard_height_desc = 500
-uf.wizard_size = (900, 700)
+uf.wizard_size = (1000, 700)
uf.wizard_image = WIZARD_IMAGE_PATH + 'minimise.png'
r24697 - /branches/zooming_grid_search/user_functions/minimisation.py