R4DS-2e Ch. 18

summarize()

{dplyr}

summarize data usually by grouping variable

group_by()

{dplyr}

group data by levels of column

sd()

{stats}

compute standard deviation

coalesce()

{dplyr}

combine vectors by returning the first non-missing value at each position

pivot_wider()

{tidyr}

pivot data frame to be wider

geom_bar()

{ggplot2}

create bar chart based on counts in data

c()

{base}

create vector of numbers, characters, etc.

max()

{base}

compute maxima of input values

ggplot()

{ggplot2}

create a plotting area

is.na()

{base}

determine whether elements of vector are missing

mean()

{base}

calculate mean of elements of vector

na_if()

{dplyr}

replace values with NA

length()

{base}

return number of elements in a vector

year()

{lubridate}

return or set year component of a date-time

tibble()

{tibble}

create tibble

count()

{dplyr}

count unique values of variables

anti_join()

{dplyr}

join two data sets dropping all observations in x that have a match in y

tribble()

{tibble}

create row-wise tibble

everything()

{tidyselect}

select all variables

aes()

{ggplot2}

create aesthetic mappings between data and plot

distinct()

{dplyr}

select only unique/distinct rows from data frame

library()

{base}

load R packages

complete()

{tidyr}

complete a data frame with missing combinations of data

fill()

{tidyr}

fill in missing values

min()

{base}

compute minima of input values

n()

{dplyr}

return current group size

factor()

{base}

encode vector as factor

The end!