psyteachr_fqa Ch. 05

filter()

{dplyr}

keep rows based on values of columns

group_by()

{dplyr}

group data by levels of column

c()

{base}

create vector of numbers, characters, etc.

sum()

{base}

sum elements of vector

count()

{dplyr}

count unique values of variables

str()

{utils}

return object structure

mutate()

{dplyr}

create or modify data columns

n()

{dplyr}

return current group size

mean()

{base}

calculate mean of elements of vector

The end!