data.table (R)

Introduction

Introduction

data.table() function

alt loading (fread; fwrite)

melt/dcast

:= stuff

.N

..select_cols

"with" in 3rd part of [,,], or first?

setkey

.SD

.SDcols

vector using .() in things

whole h3 on data.tables?

df[a,b,c]

on a, don’t have to use

df$x==3

, can just do

x==3?

on b, can do old way

c("a", "b")

or new

.(a,b)

can do 3th col using .SDcols

joins in data.table