//相对平均提高标准
double RelativeMeanImprovementCriterion::GetValue(const OptimizerState& state, std::ostream& message) {
double retVal = numeric_limits<double>::infinity();
//如果已经记录了5个以上损失值了
if (prevVals.size() > 5) {
//取队首的值
double prevVal = prevVals.front();
//如果已经有10个值了，就把队首的值删掉
if (prevVals.size() == 10) prevVals.pop_front();
//用队首的值减去最新的值，除以队列的长度，得到队列的平均提高
double averageImprovement = (prevVal - state.GetValue()) / prevVals.size();
//用队列的平均提高除以当前值得到提高相对于当前值的比例
double relAvgImpr = averageImprovement / fabs(state.GetValue());
message << setprecision(4) << scientific << right;
message << " (" << setw(10) << relAvgImpr << ") " << flush;
//将提高比例保存到retVal中
retVal = relAvgImpr;
} else {
message << " (wait for five iters) " << flush;
}
//将当前迭代的损失添加到损失列表尾部
prevVals.push_back(state.GetValue());
//返回提高的比例
return retVal;
}
double RelativeMeanImprovementCriterion::GetValue(const OptimizerState& state, std::ostream& message) {
double retVal = numeric_limits<double>::infinity();
if (prevVals.size() > 5) {
double prevVal = prevVals.front();
if (prevVals.size() == 10) prevVals.pop_front();
double averageImprovement = (prevVal - state.GetValue()) / prevVals.size();
double relAvgImpr = averageImprovement / fabs(state.GetValue());
message << setprecision(4) << scientific << right;
message << " (" << setw(10) << relAvgImpr << ") " << flush;
retVal = relAvgImpr;
} else {
message << " (wait for five iters) " << flush;
}
prevVals.push_back(state.GetValue());
return retVal;
}
