Math 263 Fall 2012

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R/XL Assignment #3 update

Please note that for R/XL Assignment #3 I posted Clarifications.html in which I answer some questions formulated by Jun.

Exam Dates

I updated dates in the syllabus, including the date of the Final Exam. As you know, Midterm dates and Review Session dates are also listed on the PDF calendar. I also updated Midterm 1 Info to reflect sections covered so far. The sample test shall not be updated, so please just skip questions in topics which will not be covered.

Old Midterm 1 for practice

An old Midterm 1 can be found under the exams tab. A version with answers can also be obtained there.

Histograms and Boxplots with R

You will find a demo file for histograms and boxplots done with R in a file that is stored in class notes for Chapter 1. See the sidebar for entry Class notes/files. Here is the direct link to the file. You can use it in several ways. This is an R script file, so you can run it completely by doing source("damage.R"). You can also execute it line-by-line by doing copy-and-paste. Better ways of stepwise execution exist.

First Excel/R assignment is here!

You will find it under the Excel/R tab. All paper homework assignments will be posted there. Please follow the Instructions document, typically provided in the Microsoft Word format. Type in the answers directly into this document, and paste your graphs, tables, images, etc. in the order the questions are asked. You should also paste in the R commands and their output. Use fixed width fonts to include such content, to result in a maximally readable document.

Office hours

Semester: Spring, 2020 (permanent)

Personnel	Day of the Week	Hour	Room	Comment
Marek Rychlik	MW	12:45-1:00pm	Math 528A Zoom link	Mini-office hour before class (Zoom)
Marek Rychlik	MWF	1:50-2:15pm	Mini-office hour after class	Mini-office hour after class (Zoom)
Marek Rychlik	MWF	2:15-3:15pm	MATH 605	Regular Office Hour (Zoom)

Chapters
- Chapter 1-2
- Chapter 3
- Chapter 6
- Chapter 7
- Chapter 8
- Chapter 9
- Chapter 12
Chapters 1 and 2 - Fundamentals
- The definitive guide on how to calculate the five-number summary by hand
- How to make a five-number summary with R?
- A detailed definition of a Quartile
  
  There is not a single way to find quartiles! See this insightful discussion
- Interquartile range (IQR)
- Wikipedia's skewness of distribution article. Note: left-skew (right-skew) means left tail is longer than the left (right). Also left-skew = negative skew and right-skew = positive skew, using another terminology.
- Download R from here
- Download RExcel from here
  
  RExcel Video
  
  RExcel Wikipedia page
  
  A local copy of RAndFriendsSetup.exe. May be outdated! Use only if you cannot obtain a copy from the distribution server in Austria. Disclaimer: I do not take any responsibility for the functioning of this third-party file, or the possibility that it may contain malware.
  
  A third party installation instructions. Disclaimer: I do not know if these work, and I do not take responsibility for their content, or possible malware on this website.
- PDF files explaining how to do linear regression with R
- A page explaining how to do linear regression with Excel.
- Local SimpleR resources
- Wikipedia article on the sum of squares and coefficient of determination
- Class notes on regression and sum of squares
  
  2011 lecture notes example (by hand)
  
  Exact linear relationship example (PDF).
  
  Non-Exact linear relationship example. Contains an R regression calculation example, and a full calculation of the sums of squares (PDF).
Chapter 3 - Design of Experiments
- Experimental Unit discussion.
- Statistical unit definition on Wikipedia.
Chapter 6 - Inference with Confidence
- On Confidence Intervals
- On Hypothesis Testing
Chapter 7 - Hypothesis testing
- On doing the t-test with R
- The two-sample t-test
- Wikipedia article on the Welch's test with the Welch-Satterthwaite formula for the number of degrees of freedom. Note that this is the test described in the book and implemented by the R function t.test, for the situation when sample sizes are uneven and we have no reason to believe that the two populations have identical variances.
- An excellent Wikipedia summary of several variants of the t-test used for a number of distinct situations (such as two-sample test when the variances of both populations are believed to be the same).
- A two-sample t-test in R for the example presented in class:
- An R example
Chapter 8 - Confidence intervals and significance tests for proportions
- R examples based on WebAssign questions:
  
  Single sample R examples
  
  Two samples R examples
  
  A PDF document on proportions. Calculations of confidence intervals and significance tests done in R, but can be easily followed with most calculators.
  
  An R file prop_lib.R, which automates confidence intervals and significance tests for two proportions. The file defines one's own function that performs all steps of the analysis, somewhat like the built-in function 't.test' does for two means.
Chapter 9 - the chi-square test and two-way tables

An R example

A PDF with a chi-squared test.

Another site illustrating using R for chi-squared test for two-way tables. The example uses a file with heart attack data which can be found here (please note that you will find there a number of other useful R examples). The particular file that needs to be read is this file. Here is a local mirror of this site.

An example of how to run the scripts and read data with R.
Chapter 12 - One-way ANOVA

R examples

A nice example of one-way ANOVA with boxplots and linear model fitting. Also, illustrates working with lists ('sapply') and splitting data by levels of a factor ('split').

An R example of one-way ANOVA with pairwise t-test (no data appears to be available, just the sequence of R commands).

A very cojent explanation of 2-way ANOVA.
Please turn in Excel assignments as hard copy, with every sheet bearing your name, before class on the due day.
Assignment
- XL/R 1
- XL/R 2
- XL/R 3
- XL/R 4
- XL/R 5
- XL/R 6
- XL/R 7
- XL/R 8
Excel/R Assignments

Assignment 1 - due date: September 7 (before class)

Go to the assignment folder

Assignment 2 - due date: September 26 (before class)

Go to the assignment folder

Assignment 3 - due date: September 28 (before class)

Go to the assignment folder

Assignment 4 - due date: October 29 (before class)

Go to the assignment folder

Assignment 5 - due date: November 2 (before class)

Go to the assignment folder

Assignment 6 - due date: November 17 (Saturday; 'before class' does not apply) (before class)

Go to the assignment folder

Assignment 7 - due date: December 1 (preliminary due on 12/01, extra credit, hard copy due 12/05) (before class)

Go to the assignment folder

Assignment 8 - due date: December 1 (preliminary due on 12/01, extra credit, hard copy due 12/05) (before class)

Go to the assignment folder
Data sources
Video Tutorials
- Browse all videos I recorded (for Windows Media Player).
More R resources
- Useful documents at CRAN
- Install R, RExcel and auxillary software using the RAndFriends installer. This software is Windows only. Helpful information can be found at the download site.
- Download RStudio. RStudio is an alternative to the plain R Console which comes with every installation of standalone R. It also replaces some functionality of RExcel under Windows by allowing easy transfer of images from R to other documents, such as MS Word documents. RStudio works on all major platforms, so it is a good choice for Mac OS users.
- Information on running Windows programs on Apple computers can be found at this Apple site. DISCLAIMER: You should be an expert user of your Mac or find competent help to run Windows on Mac, or complete data loss may result from a botched installation.
- A list of R tutorials.
- A list of R cheatsheets, especially this one.
- http://www.statmethods.net/ - a reference for many commonly used methods.
- http://www.oga-lab.net/RGM2/images.php?show=all&pageID=2007 - a rich review of R graphical capabilities.
Exams
Midterm 1

Midterm 1 Information

Obtain a copy of old Midterm 1 here.

Answers to the old Midterm 1.
Midterm 2
- Midterm 2 Information
- Obtain a copy of old Midterm 2 here.
- Answers to the old Midterm 2.
Midterm 3
- Midterm 3 Information
- Midterm 3 Download
The final

The Final Information
Grading Multiple Choice Questions

When the question requires choosing one correct answer from many

NOTE: TRUE/FALSE questions are a particular case of questions of this kind.

Only one answer must be checked. Checking more than one answer or zero answers results in a zero score.

When the question implies that many answers could be correct
Every incorrect answer cancels one correct answer.