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Appendix B. CD Tools    307

                                    The user can specify the desired pattern directly on the grid, either by  clicking
                                  each grid cell or by dragging the mouse over grid cells, then inverting the previous
                                  values of those cells. "Clear Window" clears the whole grid.
                                    In order to use the network as a CAM device, proceed as follows:
                                  1. The prototype patterns must either be loaded or specified in the grid, and then
                                    memorized  using  the  "Store"  button.  When  loading  from  a  file,  they  are
                                    immediately stored if  the  "Load and Store" option is set. Using the scroll bar,
                                    each of the stored prototypes can be inspected.
                                  2. Choose  "Random serial" in  the combo box  for  asynchronous updating of  the
                                    weights. In  "Full serial", mode the neurons are updated in sequence from (1,l)
                                    to (m, n).
                                  3. Draw or load in the grid the unknown binary pattern to be classified. Random
                                    noise with uniform distribution can be added to this pattern by clicking on the
                                    button "Add Noise". When needed, use the "Clear Window" button to wipe out
                                    the pattern from the grid.
                                  4. Use "Recall" to train the net until the best matching prototype is retrieved. Use
                                     "Step"  to  inspect  the  successive states  until  the  final  state. The  "Used as  a
                                    Classifier"  option  should  be  selected  before  "Recall"  to  impose  the  final
                                    selection of  the best matching prototype; otherwise the final state is displayed.
                                    The weight matrix can be inspected with the "Get Weight" button.

                                     A new experiment with other dimensions must be preceded by  "Clean", wiping
                                  out all the stored prototype patterns.
                                     In order to use the network for discrete relaxation matching, proceed as follows:

                                  1. Dimension the grid with the set cardinalities of the two sets to be matched.
                                  2.  Fill in the weight matrix using the "New Weight" button. The weights can be
                                     edited either directly or loaded in from a file with the same format as above with
                                     extension .HNW. Only one half of the matrix has to be specified if the "Matrix is
                                     Symmetric" option is selected. In this case, when editing cell (ij), the cell G,i)
                                     gets the same value.
                                  3. When  filling  in  the  weight  matrix,  it  is  convenient  to  start  by  clicking  the
                                     "Weights Initialisation" button, which initializes all matrix values with the one
                                     specified in the text box. See section 6.4.4 for the choice of weight values.
                                  4. Choose the  "Full parallel" mode  in  the  combo box,  imposing a synchronous
                                     updating of all neurons.
                                   5. Click "Step" to update the assignment probabilities.

                                     When performing several experiments with the same weight matrix, it is usually
                                   convenient to define it only once and save it using the "Save" button. The weight
                                   matrix can also be cleared using the "Clear Weight" button.

                                   Author: Paulo Sousa, Engineering Faculty, Oporto University.
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