Acknowledgement and References

We extend our heartfelt gratitude to the R Core Team for their dedication and invaluable contributions to the R language. We thank Hadley Wickham, Davis Vaughan, Maximilian Girlich, et al., for their great work on developing and maintaining the tidyr package, that has evolved into one of the most used tools for data analysis in the R and broader data science community.

This serial tutorials has extensive reference to the official tidyr documentation. Substantial adaption and optimization are made to offer more streamlined content structure, self-explanatory and practical illustrating examples, and improved texts, etc., aiming for improved understanding, memorability, and systematic learning.