int samann_adapt_unit | (unit, eta, alpha, options, pass, lambda, set_dist, map_dist) |
UNIT | *unit | A pointer to a UNIT structure. |
double | eta | The coefficient eta (the learning rate) of the backpropagation rule. |
double | alpha | The coefficient alpha (the momentum term) of the backpropagation rule. |
long | options | See note below. |
int | pass | The pass for which this function is called: 1 or 2 - see below. |
double | lambda | The Sammon constant - see samann_lambda. |
double | set_dist | The distance in the original set between the sample shown in pass 1 and that shown in pass 2. |
double | map_dist | The current distance in the map between the sample shown in pass 1 and that shown in pass 2. |
HISTU | (Don't) store history of unit values at each update. |
HISTT | (Don't) store history of unit thetas at each update. |
HISTW | (Don't) store history of weights at each update. |
SAACCUM | (Don't) accumulate the delta's. |
SAUPDATE | (Don't) update the weights. |
SAOLDPRP | (Don't) backpropagate using the original weights (i.e., the weights as they were before this update of the network). |
Note that the individual HIST-flags and SAMANN-flags may be OR'ed together. The update process is divided into two phases: first, the weight-change is computed (optionally, only if SAACCUM is set), then the actual weight-change is done (optionally, only if SAUPDATE is set). Also, note that by default (when SAOLDPRP is not set) the newly calculated weight-change is performed immediately (assuming SAACCUM and SAUPDATE are set), while the standard rule, in which weight-changes are made effective only in the next cycle, requires SAOLDPRP to be set. In effect, not specifying SAOLDPRP causes a random disturbance of the minimization process which might result in a speed up, but may cause problems in difficult learning processes. Furthermore, note the following for (SAACCUM, SAUPDATE) - pairs:
0 | 0 | Combination does not make sense (nothing is done). |
0 | 1 | Yields no backpropagation, only updates. |
1 | 0 | Yields only backpropagation, no updates. |
1 | 1 | Specifies normal mode, i.e. backpropagation and update. |
This function is used by samann_adapt_net.
This document was generated using api2html on Thu Mar 5 09:00:00 MET DST 1998