APPENDIX 1: ABOUT THE MOVIES




			     USING MOVIES IN MATLAB


    A movie of successive figures can be created in matlab using its built 
in functions.  The information for frame j is saved in column j of a large 
matrix which is initialized before creating the movie.  As a result, matlab 
allows variables (such as the matrix) to be saved so that it can be retrieved 
later and played back.  Specifics on the matlab commands 'movie', 'getframe' 
and 'moviein' can be obtained from the matlab help files (help <command>).  
One drawback of the movies is that the range of values for the axes is not 
stored.

    In the subroutines of the brain program, each time the net is altered (ie. 
network figure changes), the previous frame is saved.  This allows for 
the complete history of a growing net to be recorded.  Since the replay will 
not show the appropriate (x,y) coordinates of each neuron, it may be important 
to visualise when a neuron receives an input.  The rectangular boxes which 
select neurons for input can be activated on the network figure (as well as the 
input field figure).  This allows the rectangle to be saved in the previous 
movie frame.  As a result, when playback occurs, the neuron which is to receive 
input in the next frame can be discerned.  All frame saving and matrix updating 
is done by the brain program after each step.

    To save a movie (eg. before quitting), clicking on the 'save' button 
will record all previous steps (note: not current figure) to the default 
file 'movie.mat' in the matrix M.  This filename must be hardcoded in the 
program due to constraints by matlab, but can be changed by altering the 
'saveit.m' file.  A word of warning before saving is that these matricies can 
get very large and take up a huge amount of disk space (70 frames ~ 10 Meg.).  
However, these files can be compressed using the UNIX 'compress' command, which 
reduces size by 95+%.

    To restore a saved movie, it must first be loaded in matlab.  The commands 
 described in the following section are described in much more technical 
detail in the document 'refguide.txt'. Any number of frames can be replayed at 
any chosen speed.  To get an accurate movie, the colour scheme must be changed 
to 'cool' and to eliminate the false axes, these must subsequently be shut off. 
 Note that before matlab plays a movie, it must first assemble the frames, so it 
plays through the entire movie once as it compiles the information.  Once this 
has been completed, it will then proceed in playing the movie at the chosen 
speed for the number of repetitions specified.