@Override
public void step() {
stateHidden.setSubVector(0, weights0.operate(stateIn));
for (int i : series(h)) stateHidden.setEntry(i, activation.function(stateHidden.getEntry(i)));
stateOut.setSubVector(0, weights1.operate(stateHidden));
}
/** {@inheritDoc} */
public double value(final double[] point) throws FunctionEvaluationException {
// compute residuals
final double[] residuals = function.value(point);
if (residuals.length != observations.length) {
throw new FunctionEvaluationException(
point, "dimension mismatch {0} != {1}", residuals.length, observations.length);
}
for (int i = 0; i < residuals.length; ++i) {
residuals[i] -= observations[i];
}
// compute sum of squares
double sumSquares = 0;
if (weights != null) {
for (int i = 0; i < residuals.length; ++i) {
final double ri = residuals[i];
sumSquares += weights[i] * ri * ri;
}
} else if (scale != null) {
for (final double yi : scale.operate(residuals)) {
sumSquares += yi * yi;
}
} else {
for (final double ri : residuals) {
sumSquares += ri * ri;
}
}
return sumSquares;
}