R
data.table
Package
data.table main page
data.table CRAN page
with many links
data.table intro
data.table tutorial
data.table beginner’s guide
data.table R tutorial
RIP tutorial
Long cheatsheet
Data transformation with data.table cheat sheet
Examples for common tasks
Stackoverflow Q&A
data.table and tidyverse side by side comparison
data.table vs. dplyr
FH examples
Cole Beck material
Understanding joins
and
here
and
here
and especially
this
Left joins
including use of
on
and
i.
prefix
Rolling join
Purpose of setting a key and use of on=
Tests
Adding multiple columns
Transforming multiple columns
Nice table looking example
Non-equi merge in epidemiology
Non-equi join
Sequential counter for rows within groups
Updating a list of columns
Set multiple columns with a named list
Setting attributes of columns
Lookup table
Lookup for multiple columns
Lookup and value replacement
Computing statistics on all numeric columns
Filter rows by column value ranges
Finding columns meeting a test condition
Changing Inf in any value of any variable to NA