First the ART1 initialization function ART1_Weights has to be selected from the list of initialization functions.
ART1_Weights is responsible to set the initial values of the trainable
links in an ART1 network. These links are the ones
from F
to F
and the ones from F
to F
respectively.
The F
F
links are all set to 1.0 as described
in [CG87a]. The weights of the links from F
to F
are
a little more difficult to explain. To assure that in an initialized
network the F
units will be used in their index order,
the weights from F
to F
must decrease with increasing index. Another
restriction is, that each link-weight has to be greater than 0 and
smaller than 
. Defining 
as a link-weight from a
F
unit to the jth F
unitthis yields
To get concrete values, we have to decrease the
fraction on the right side with increasing index j and assign this
value to 
. For this reason we introduce the value
and we obtain
is calculated out of a new parameter 
and the
number of F
units M:
So we have two parameters for ART1_Weights: 
and
. For both of them a value of 1.0 is useful for the
initialization. The first parameter of the initialization function is
, the second one is 
. Having chosen 
and
one must press the 
-button to perform
initialization.
The parameter 
is stored in the bias field of the unit
structure to be accessible to the learning function when
adjusting the weights.
One should always use ART1_Weights to initialize ART1 networks. When using another SNNS initialization function the behavior of the simulator during learning is not predictable, because not only the trainable links will be initialized, but also the fixed weights of the network.
