Package seasonal is an easy-to-use and has an R-interface to
X-13ARIMA-SEATS, the latest seasonal adjustment software developed by
the United States Census Bureau.

Seasonal depends on the x13binary package, which downloads and
installs the X-13 binaries. To install both packages, type to the R
console:
install.packages("seasonal")

Read more about the package with vignette("seas").

The replication code shows the following:

a) Using WPI it shows how the year-on-year indicator lags the
point-on-point indicator.

b) It shows the steps involved in seasonal adjustment using package
seasonal. The code also shows how to save all the required output
files to understand the various diagnostics generated by
x-13-arima-seats program.

c) Shows how moving holiday i.e. Diwali is significant for IIP. The
codebase shows how accounting for Diwali is able to reduce the
volatility (standard deviation of the series).

d) It shows the progressive reduction in standard deviation with the
improvements described in the paper.

The code uses three data files:

a) BPPS2016_data.csv: The raw data series for WPI and IIP.

b) BPPS2016_iip_eviews.csv: The seasonally adjusted series for IIP obtained
through the application of eviews software.

c) BPPS2016_diwali.csv: The data with diwali dates