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.