Outlier detection of time series data in R
detection, outliers, r
Solution
You may have a look at the following packages available in R.
The R package `forecast` uses loess decomposition of time series to identify and replace outliers.
The R package `tsoutliers` implements the Chen and Liu procedure for detection of outliers in time series. A description of the procedure and the implementation is given in the documentation attached to the package. You may also see this post.
Problem
What are the steps needed to detect outliers in business sales data (which means there might be trends and seasonality) in R? I have learnt about ACF, PACF, residual, ARIMA model (basically, time series analysis and modelling). Can I use this knowledge to help me identify outliers? Is it also possible to ask R to pinpoint which point of data is outlier? Thank you very much.