lecture 2 lisam. statistical software.. lisam what is lisam? social network for creating personal...
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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
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