1. Aprender
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  2. Cursos
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  3. Joining Data with data.table in R
  • 1

    Joining Multiple data.tables

    Gratuito

    This chapter will show you how to perform simple joins that will enable you to combine information spread across multiple tables.

  • 2

    Joins Using data.table Syntax

    In this chapter you will perform joins using the data.table syntax, set and view data.table keys, and perform anti-joins.

  • 3

    Diagnosing and Fixing Common Join Problems

    This chapter will discuss common problems and errors encountered when performing data.table joins and show you how to troubleshoot and avoid them.

  • 4

    Concatenating and Reshaping data.tables

    In the last chapter of this course you'll learn how to concatenate observations from multiple tables together, how to identify observations present in one table but not another, and how to reshape tables between long and wide formats.

Initializing

Exercicio

Multi-key, single-key

In addition to locations, you will work with the teachers dataset in this exercise. It contains information about the teacher for each subject. The teacher of each subject does not change between semesters. Your goal is to build a new data.table containing the room allocation for each subject, using the teachers and locations data.tables.

Instruções

100 XP
  • Identify the key column(s) for joining teachers and locations and assign it as a character vector in the form c("teachers_join_key" = "locations_join_key") to the join_key variable.
  • Using the data.table syntax, right join locations to teachers using the join_key variable.