First, it is necessary to remove trends and autocorrelation from the time series.
> -wrap-foot> The use of a regression line to remove trends was motivated by the appearance of a rate/ratio correlation for d S in flies when rate parameters were simply normalized to the geometric mean.
To remove trends, we replaced the original incidence data with the residual of the linear regression between the year and the incidence data plus the mean of the incidence series.
This algorithm, instead of removing trend with a priori mathematical formulas such as linear or polynomial functions [14], [29], could evaluate the hidden dynamics of heart beat fluctuations better [9], [10], [29].
This removes trends that are common to all countries and allows the focus on asymmetric (rather than common) shocks.
Standardisation allowed for the comparison of fast- and slow-growing individuals on the same scale and removed trends related to age or stand dynamics.
This normalization removed trends introduced by sample handling, sample preparation, HPLC, mass spectrometry, and possible total protein differences.
When the observed time series presents a trend and heteroscedasticity, differencing and power transformation are applied to the data to remove the trend and stabilize the variance before the ARIMA model can be fitted.
To be clearer: Twitter wouldn't – and didn't – actively censor or remove this trend.
Some have suggested that to remove the trend, the terms may be specified in first differences, which often yields results showing that the effect of public capital is small, sometimes negative, and generally not statistically significant (Munnell 1992; Gramlich 1994).
