2.1 Descriptive Statistics
2.1.1 Frequency distribution
https://en.wikipedia.org/wiki/Seven-number_summary
Grenander’s mode https://search.r-project.org/CRAN/refmans/modeest/html/modeest-package.html
2.1.2 Measures of statistical characteristics
Mean, median, …
https://en.wikipedia.org/wiki/Trimean https://en.wikipedia.org/wiki/Interquartile_mean https://en.wikipedia.org/wiki/Interquartile_range https://en.wikipedia.org/wiki/Midhinge https://en.wikipedia.org/wiki/Quartile