Time Series
作者：Steven White
1. Long term trend
1.1. Increasing
1.2. Decreasing
1.3. Constant
2. Seasonal Variation
2.1. Regular
2.1.1. Highs
2.1.2. Lows
2.1.3. Period
2.2. Irregular
3. Residuals
3.1. Less than 10% of variation
3.1.1. Accurate model
3.2. More than 10% of variation
3.2.1. Significant error in forecast