Lecture 2

LISAM. Statistical software.

LISAM

What is LISAM? Social network for Creating personal pages Creating courses

Storing course materials (lectures, documents, useful links) Publishing assignments to certain student groups (labs,

project work) Uploading and submitting solutions to assignments

electronically Correcting and grading the solutions

Communication between students and teacher

http://lisam.liu.se

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How it looks like when you logon

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Panels

Menu Newsfeed: you find comments from people and courses

you have chosen to follow Messages: important information from

teachers/administrators in your courses.

Important menus: About me (edit the profile, set the default language) My courses: See all courses that you registered yourself

for. About LISAM help information

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If the webpage is in Swedish

About meEdit your profile

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Accessing a course

Mina kurser/ My courses

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Course structure

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Course structure

Syllabus: compressed information about the course, teaching, examination and admission requirements

Course documents: basic course material: lectures, files (uploaded by teacher)

Collaborative workspace: teachers and students can publish files there and make comments

Newsfeed: Teachers and students may start a conversation there

Announcements: information from teacher Timetable: link to schedule in TimeEdit Submissions: Here you may find your labs/assignments and

submit the answer Assessment record: The overview of your grades

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Course menus

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Note that each lab/assignment has a deadline and an end date

Submit a report

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Statistical and data mining software

Commerical SAS Minitab SPSS Matlab Microsoft SQL Server

Free of charge: R WinBugs Python GGobi

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SAS SAS

Basic Module SAS Enterprise Guide SAS JMP …

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SAS

Learn: How SAS is started What is Library What's in the Editor, Output, Log What's in the Results How to create a library How to import XLS document to the library Note data material (Column attributes) Write a simple computer program and save the file

proc. gplot data = sashelp.class; plot height * weight; run;

Run the program Sas file upload. Help (contents, index, search, SAS/GRAPH, SAS/STAT)

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proc import datafile=’C:\Customers.xlsx' dbms=xlsx

out=Customers;

sheet='Sheet1';

run;

Minitab

Learn: Import data Look through the menus Run regression Make a plot

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R

R is a real computer language with full flexibility Constantly increasing amount of packages (new

research) Free of charge Website: http://www.r-project.org/ Code Editor: http://rstudio.org/

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Software: use RStudio

Install R: http://www.r-project.org/ Install RStudio: http://rstudio.org/

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Program

Execution console

Plots

Workspace

Basics in RStudio

Important to know:Create a new file and save it (File menu)Running one line or entire code (Edit menu)Running one line in consoleWorkspace (Observe, Save, Clear)Setting current directory (Tools)Installing new package (Packages tabs)

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Call help

Specific function help(function)

Help browser help.start()

Search for something in help help.search(“expression”)

Quick reminder of function arguments: args(function)

Examples of how to use function: example(function)

If some method is not installed on the computer: RSiteSearch(”expression")

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Introduction

R is case-sensitive (A and a) Each command on a new line Comment:

#R is a very cool language!

Initialize/set the variable

Use-> or <-

a<-3

3->b

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Vectors

Create a vectorx<-c(1,3)

See the resultx

print(x)

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Sequence

Either‘: ‘ or seq()

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Use matrix()

a<-matrix(values,nrow=m,ncol=n)

Values should be listed columnvise

nrow= and ncol= can be skipped

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Matrices

Index

Positive index

x[1,6] x[2:10]

Negative index

x[-(1:5)] all except 1:5

Entire column or row

x[2,] entire column 2

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Vectors and matrices of the row length can be collected into a data frame

• Used to store the data of different types into a single table

Use data.frame(object 1, object 2, … , object k)

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Data frame

Any object in the data frame can be retrieved by

dataframe$object

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Data frame

Read data from Excel file

1. Save as ”comma-separated file”(csv)

2. Use

Dataframe<-read.csv2(file_name)

Exercise: Use Excel file Airlines.xls and import it to R

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Conditioning and loops

If (x==3) {……} else {…}

for (i in 2:99) {…}

while(x!=29) {…}

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for (name in expr1 )

{

…

}

while (condition)

{

…

}

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Loops

Function writing must always end with writing the value which should be returned!

You may also use ”return(value)” to show what value the function should return

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Writing your own functions