Method LearningRate

src/app/linear_method/learning_rate.h:9–12

class LearningRate {
 public:
  LearningRate(const LearningRateConfig& conf) : conf_(conf) {
    CHECK_GT(alpha(), 0);
    CHECK_GE(beta(), 0);
  }
  ~LearningRate() { }

  V eval(V x = 0) const {