Exercícios 1 - Introdução ao R
1.1 Basta Mudar o Diretório?
getwd() = verificar diretório
setwd("/Users/veronica/Desktop/Discliplia_R/Temp1")
getwd()
save.image()
save.image(file="R_temp")
Ao fechar o R salvar o workspace

1.2 Um Comando Perigoso
rm(list=ls())
Se os scripts forem salvos podem ser executados novamente.
    
1.3 Classes de Objetos
1.3.1.
help("letters")
==Description

Constants built into R.

Usage

LETTERS
letters
month.abb
month.name
pi
Details

R has a small number of built-in constants.

The following constants are available:

LETTERS: the 26 upper-case letters of the Roman alphabet;

letters: the 26 lower-case letters of the Roman alphabet;

month.abb: the three-letter abbreviations for the English month names;

month.name: the English names for the months of the year;

pi: the ratio of the circumference of a circle to its diameter.

These are implemented as variables in the base namespace taking appropriate values.==

1.3.2.
class(letters)
"character"

class(LETTERS)
"character"

1.3.3.
Função factor().
letters <- factor(letters)
LETTERS <- factor(LETTERS)