r-dplyr-wrangling

Governs reshaping a data frame in R with dplyr before it feeds a dashboard: select and rename columns, filter rows (including missing values), make or recode columns with mutate and case_when, group and summarise, count, and work within groups. Use when writing or fixing dplyr code, when a filter returns zero rows or a recoded column has unexpected NA, when a grouped summary has missing groups or stays grouped, or when explaining these verbs to a learner. Do not use for reading files or APIs (r-data-prep), statistical tests (r-stats-foundations) or chart code (r-dashboard-design).