# Data for replication

Here is the data needed for replicating the experiments. 

This paper uses a PM 2.5 data of the hourly changes of air quality in the Central/Western district of Hong Kong, which can be download from http://www.aqhi.gov.hk/. The time period ranges from 2017-04-01 00:00:00 to 2018-03-31 23:00:00.

The data includes four columns, where the first two columns store the date and hour of the data collected. The third column presents the station where the data are collected. The last column records the PM 2.5 data that we use to perform the trend filtering analysis.
