R4DS-2e Ch. 22

library()

{base}

load R packages

sum()

{base}

sum elements of vector

group_by()

{dplyr}

group data by levels of column

summarize()

{dplyr}

summarize data usually by grouping variable

arrow()

{grid}

plot arrows

filter()

{dplyr}

keep rows based on values of columns

desc()

{dplyr}

order in descending order

tibble()

{tibble}

create tibble

arrange()

{dplyr}

change order of rows based on values of columns

collect()

{dplyr}

retrieve data from a database into a local tibble

The end!