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Data Analysis & DataScience with R

Basic Data Management

By Marin Fotache

Al.I. Cuza University of Iași

Faculty of Economics and Business Administration

Department of Accounting, Information ystems andtatistics

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Topics

 Adding column(varia#les◦ New columns defined through expresssions

◦ Function transform

%emoving varia#les -columns◦ Directly, e.g. invoices_2 <- invoices_1[-10]

◦ Directly, e.g. df$column.to.remove <- NULL

◦

Indirecty (by copying a data frame and specifiyng thevariables NO to be removed!

◦ "ith function remove.vars from pac#age gdata 

◦ "ith function Varro! from pac#age ata"om#ine

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Topics (cont.)

 %ecoding varia#les -values◦ $ecode with filter (subsetting!

◦ Divide continuous variable x into factor with n levels%

cut%& n'

◦ Divides a continuous variable x into n intervals by

selecting n&' eually spaced rounded values (pretty

brea#points!% !rett(%& n'

%enaming varia#les -columns

◦ "ith function names

◦ "ith function rename from pac#age res)a!e

◦ "ith function rename.vars from pac#age gdata

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Topics (cont.)

C&ange order of t&e columns◦ "hen copy a data frame

◦ "ith function *ove+ront from pac#age ata"om#ine

u#setting data frames

◦ )sing suare brac#ets [ ]

◦ "ith function ,)ic)

◦ "ith function su#set

orting data

Uni/ue and duplicated values

Data sampling

Basic 0descriptive0 functions

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