Generic Comparison Plot Report

library(qgert)

Summary

tl;dr. Given two directories dir1 and dir2, containing plot files stored in pdf or png-format, the follwoing command

qgert::create_comparison_plot_report(ps_right_dir = dir1, ps_left_dir = dir2)

creates a RMarkdown report (generic_comparison_plot_report.Rmd) in the current directory where analogous plots from the two directories are shown side-by-side. The RMarkdown report is automatically rendered into a pdf document (generic_comparison_plot_report.pdf) which can also be found in the current working directory.

Background

Results of statistical analyses are often presented as diagrams. When we are interested in the effect of changes in the analysis on the results, they should be visible in the comparison of the result diagrams. Hence there is a need for comparing the same type of diagram for different context parameters.

Purpose

Given two directories each containing a set of plot files stored either as pdf-files or in png-format. Furthermore, we assume that the plot files in the two directories normally come in pairs with the same file name. The function create_comparison_plot_report() from the qgert package takes the path to the two directories as arguments and shows the plots which are stored in files with the same name side-by-side in a RMarkdown report. This makes the comparison of the two plots a lot easier.

Result

The result of running the function create_comparison_plot_report() is a report that shows pairs of analogous plots side-by-side. An example of such a pair of plots is shown below.

If any of the plot files is missing in one of the directories a placeholder directory showing the string ‘NA’ is included. This is shown below.

Customisation

As shown in the summary section above, the function create_comparison_plot_report() requires only the two directories to be specified as input parameters. But there are more options with which the generated report can be modified and enhanced. The generated report is based on a template which contains placeholders allowing to parameterize the generated report. The parametrisation allows to insert specific characteristics of a given report into the RMarkdown source file. These characteristics include the title, the author and the output format of the report. The specific information is passed as a list to the argument pl_repl_value. Hence the following call to the function create_comparison_plot_report() modifies the title and the author in the report.

qgert::create_comparison_plot_report(ps_right_dir = dir1, 
           ps_left_dir = dir2,
           pl_repl_value = list(title = "Test Generic Comparison Plot Report", 
                                author = "Peter von Rohr")

As can be seen from the following screenshot, the title and the author have been modified according to the specified input.

The following table gives a list of all available parameters for the function create_comparison_plot_report()

Parameter	Description
ps_right_dir	Plots shown on the right-hand-side in the report
ps_left_dir	Plots shown on the left-hand-side in the report
ps_tmpl_path	Path to alternative report template
ps_diagram_na_path	Path to missing diagram replacement
ps_report_text	Additional text to be included at the beginning of the report
pl_repl_value	List with placeholder replacement values
ps_out_path	Alternative path to report document
pb_keep_src	Flag to keep source files
pb_session_info	Flag to include session information
pb_force	Flag to overwrite existing report
pb_debug	Flag to include debugging information
plogger	log4r logger object