- (void)updateWithYValue:(CGFloat)newY {
    
    if (!isnan(newY)) {

        if (!_shouldResetConfiguration) {
            _minValue = newY;
            _maxValue = newY;
            _startValue = NO;
            _didCheckerFindingTarget = NO;
            _shouldResetConfiguration = YES;
        } 
 
else {
            if (!_didCheckerFindingTarget) {
                _maxValue = MAX(_maxValue, newY);
                _minValue = MIN(_minValue, newY);
                CGFloat gapFromMaxValue = (ABS(_maxValue - newY));
                CGFloat gapFromMinValue = (ABS(newY - _minValue));
                
 
if (gapFromMaxValue >= self.minDistanceChangeForAllowRecordNumber) {
                    _didCheckerFindingTarget = YES;
                    _findingTopValue = NO;
                    _criticalValue = newY;
                    _maxValue = newY;
                    _foundTargetCount = 1;
                } 
 
else if (gapFromMinValue >= self.minDistanceChangeForAllowRecordNumber) {
                    _didCheckerFindingTarget = YES;
                    _findingTopValue = YES;
                    _criticalValue = newY;
                    _minValue = newY;
                    _foundTargetCount = 1;
                }
            } else {
                if (_findingTopValue) {
                    if (newY >= _criticalValue) {
                        _maxValue = MAX(newY, _maxValue);
                        _minValue = newY;
                        CGFloat gapFromMaxValue = (ABS(_maxValue - newY));
                        if (gapFromMaxValue >= self.minDistanceChangeForAllowRecordNumber) {
                            _criticalValue = newY;
                            _findingTopValue = NO;
                            if (_foundTargetCount % 2 == 0) {
                                [self addOneChangeCount];
                            }
                        }
                    } else {
                        CGFloat gapFromMaxValue = (ABS(_maxValue - newY));
                        _minValue  = MIN(_minValue, newY);
                        CGFloat gapFromMinValue = (ABS(newY - _minValue));
                        if (gapFromMaxValue >= self.minDistanceChangeForAllowRecordNumber) {
                            _foundTargetCount += 1;
                            _criticalValue = newY;
                            _minValue = newY;
                            _findingTopValue = NO;
                            if (_foundTargetCount % 2 == 0) {
                                [self addOneChangeCount];
                                printf("==============>2\n");
                            }
                        } else if (gapFromMinValue >= self.minDistanceChangeForAllowRecordNumber) {
                            ///異常，需要忽略一半波形
                            _criticalValue = newY;
                            _maxValue = newY;
                            _findingTopValue = YES;
                        }
                    }
                } else {
                    if (newY <= _criticalValue) {
                        _minValue = MIN(newY, _minValue);
                        _maxValue = newY;
                        CGFloat gapFromMinValue = (ABS(newY - _minValue));
                        if (gapFromMinValue >= self.minDistanceChangeForAllowRecordNumber) {
                            _foundTargetCount += 1;
                            _criticalValue = newY;
                            _findingTopValue = YES;
                            if (_foundTargetCount % 2 == 0) {
                                [self addOneChangeCount];
                            }
                        }
                    } else {
                        CGFloat gapFromMinValue = (ABS(newY - _minValue));
                        _maxValue  = MAX(_maxValue, newY);
                        CGFloat gapFromMaxValue = (ABS(_maxValue - newY));
                        if (gapFromMinValue >= self.minDistanceChangeForAllowRecordNumber) {
                            _foundTargetCount += 1;
                            _criticalValue = newY;
                            _maxValue = newY;
                            _findingTopValue = YES;
                            if (_foundTargetCount % 2 == 0) {
                                [self addOneChangeCount];
                            }
                        } else if (gapFromMaxValue >= self.minDistanceChangeForAllowRecordNumber) {
                            ///異常，需要忽略一半波形
                            _criticalValue = newY;
                            _minValue = newY;
                            _findingTopValue = NO;
                        }
                    }
                }
            }
        }
    }
}

假設第一個點為最低值，根據下一個點判斷趨勢，記錄探測接下來的值，記錄max和min，噹噹前點達到觸發臨界差值，認定觸發了一個波峰/波谷。若為波峰，保留最高值，探測下面的值，當探測到最高點到當前點差值到達臨界值認為下到一個波谷，計數加1。