'ggplot2' Extension for Seasonal and Trading Day Adjustment with 'RJDemetra'

Provides 'ggplot2' functions to return the results of seasonal and trading day adjustment made by 'RJDemetra'. 'RJDemetra' is an 'R' interface around 'JDemetra+' (< https://github.com/jdemetra/jdemetra-app>), the seasonal adjustment software officially recommended to the members of the European Statistical System and the European System of Central Banks.

Overview

ggdemetra is an extension of ggplot2 to add seasonal adjustment statistics to your plots. The seasonal adjustment process is done with RJDemetra that is an R interface to JDemetra+, the seasonal adjustment software officially recommended to the members of the European Statistical System (ESS) and the European System of Central Banks. RJDemetra implements the two leading seasonal adjustment methods TRAMO/SEATS+ and X-12ARIMA/X-13ARIMA-SEATS.

There are 4 main functionnalities in ggdemetra depending of what you want to add in the graphic:

• geom_sa(): to add a time series compute during the seasonal adjustment (the trend, the seasonal adjusted time series, etc.).
• geom_outliers(): to add the outliers used in the pre-adjustment process of the seasonal adjustment.
• geom_arima(): to add the ARIMA model used in the pre-adjustment process of the seasonal adjustment.
• geom_diagnostics(): to add a table containing some diagnostics on the seasonal adjustment process.

Installation

Since RJDemetra requires Java SE 8 or later version, the same requirements are also needed for ggdemetra.

ggdemetra is not on CRAN for the moment. To use it you need to install the GitHub version:

# install.packages("devtools")
devtools::install_github("AQLT/ggdemetra")

Usage

To add the seasonal adjusted series and the forecasts of the input data and of the seasonal adjusted series:

library(ggplot2)
library(ggdemetra)
 
p_ipi_fr <- ggplot(data = ipi_c_eu_df, mapping = aes(x = date, y = FR)) +
    geom_line() +
    labs(title = "Seasonal adjustment of the French industrial production index",
         x = "time", y = NULL)
p_sa <- p_ipi_fr +
    geom_sa(component = "y_f", linetype = 2, message = TRUE) + 
    geom_sa(component = "sa", color = "red", message = FALSE) +
    geom_sa(component = "sa_f", color = "red", linetype = 2, message = FALSE)
p_sa

To add the outliers at the bottom of the plot with an arrow to the data point and the estimate coefficient:

p_sa + 
    geom_outlier(geom = "label_repel",
                 coefficients = TRUE,
                 message = FALSE,
                 vjust = 4,
                 ylim = c(NA, 65), force = 10,
                 arrow = arrow(length = unit(0.03, "npc"),
                               type = "closed", ends = "last"))
#> Frenquency used: 12

To add the ARIMA model:

p_sa + 
    geom_arima(geom = "label",
               x_arima = -Inf, y_arima = -Inf, 
               vjust = -1, hjust = -0.1,
               message = FALSE)
#> Frenquency used: 12

To add a table of diagnostics below the plot:

diagnostics <- c(`Combined test` = "diagnostics.combined.all.summary",
                 `Residual qs-test (p-value)` = "diagnostics.qs",
                 `Residual f-test (p-value)` = "diagnostics.ftest")
p_diag <- ggplot(data = ipi_c_eu_df, mapping = aes(x = date, y = FR)) +
    geom_diagnostics(diagnostics = diagnostics,
                     table_theme = gridExtra::ttheme_default(base_size = 8),
                     message = FALSE) + 
    theme_void()
    
gridExtra::grid.arrange(p_sa, p_diag,
             nrow = 2, heights  = c(4, 1))
#> Frenquency used: 12