Statistical Methods with application to Finance

Roberta Pappadà (rpappada@units.it)
February 2024

What is R?

R is a free software environment for statistical analysis and graphics:

  • it is open source
  • it includes a wide set of tools for the statistical analysis of data
  • it is an object-oriented language
  • it can be easily extended by the user

R Studio is a open source integrated development environment for R

Installing Base-R and RStudio

-> Obtain R via the Comprehensive R Archive Network (CRAN):

-> RStudio:

www.rstudio.com/products/rstudio/download/

Instructions for software installation are available at

How to Install R on Windows, Mac OS X, and Ubuntu

Getting started

The Four RStudio Windows:

  • Source
  • Console
  • Environment / History
  • Files / Plots / Packages / Help

Writing Code

R Console

type 1+2 into the console and press Enter!

Source file

collect the code into the R Script, then run selection with

  • Run button
  • Command + Enter on Mac

  • Control + Enter on Windows

  • '#' for comments

Command Line and Writing Shortcuts

Basic Data Types

  • character : 

    "a"

  • numeric:

    2, 5.2

  • integer:

    2L

  • logical:

    TRUE,FALSE

  • complex:

    2+4i

What kind of object is it?

class( ), typeof( ), mode( ), str( ), is.numeric( )
…

Basic Data Structures

  • Vector

  • Matrix

  • Array

  • List

  • Factor

  • Data frame

c( ), vector( ), seq( )

matrix( )

array()

list()

factor()

data.frame()

Some basic functions

For more details click the Help button on the toolbar!

Data visualization

  • categorical variables: pie( ), barplot( )
  • numerical variables: hist( ), boxplot( )

Use plot( ) to produce a scatter plot

  x<-c(0.5, 0.5, 2, 4, 6, 0.2, 5, 4.1)
  y<-c(0.5, 1.5, 3.2, 8, 6, 1.2, 3, 3.5)
  plot(x,y, pch=21, bg="red")
plot of chunk unnamed-chunk-1

plot of chunk unnamed-chunk-1

Installing R packages

R packages for basic functions are already available when R is installed.\

Other packages can be obtained from CRAN and its mirrors. For example, to install openxlsx., start R and type

install.packages("openxlsx")

In RStudio you can use “Install” from the Packages tab. Then type the command

library(openxlsx)

You can also click the box next to the package name.

Online resources