Download presentation

Presentation is loading. Please wait.

Published byReese Bardy Modified over 3 years ago

1
Alejandro Buren & Paul Regular Introduction to BIOL 7220 September 2012

2
What to expect from this workshop Intro to R Data summaries Create plots Run General linear models Easily extensible to glm, gam, glmm, gamm – BUT you have to know what you’re doing

3
What NOT to expect from this workshop A course in statistics A showcase of R’s capabilities

4
What is R? Environment and language for – Statistics – Graphics – Etc. Open source

5
Why use R? It’s FREE! Flexible One stop shop Large up-front cost, but BIG payoff Growing number of users Expansive!

6
Download & Install Program – R & Tinn-R installed? Packages – Required to use statistical and graphical packages not included in the base package – Install once – Load each new session

8
Vectors R has symbolic vectors which can be assigned values The traditional way to do this in R is the ’<-’ operator Possible vector names flexible – Vector names cannot start with a digit – Names are case-sensitive – Some common names are already used by R c, q, t, C, D, F, I, T,

9
Functions MANY built in functions – log() – exp() – sin() – sqrt() – mean() – max() – Etc.

10
Data Types Vectors (Numeric, Character, Logical) Matrix – All columns in a matrix must have same mode Array – N-dimensional matrix Dataframe – Columns in a data frame can have different modes. Similar to SAS and SPSS datasets Lists – Collection of objects, can be different modes and dimensions Factor

11
Data Management Import & Export Useful functions – subset – na.omit – cbind, rbind – sort – summaryBy – Operate over dataframe – Random numbers

12
Good Practice Set up a working directory Comment on each line of code Avoid attach function Define parameters in first lines of code Use standard format use.dots, OrCapitals, avoid spaces anywhere Clean up

13
Statistics & Graphics Working example – Look at data – Graph data – Run one regression and one ANOVA

14
HELP! Useful websites – Official site (http://www.r-project.org/)http://www.r-project.org/ Manuals found on this site (http://cran.r-project.org/manuals.html)http://cran.r-project.org/manuals.html – R search site (http://finzi.psych.upenn.edu/search.html)http://finzi.psych.upenn.edu/search.html – Quick-R (http://www.statmethods.net/index.html)http://www.statmethods.net/index.html – R graphics gallery (http://addictedtor.free.fr/graphiques/)http://addictedtor.free.fr/graphiques/ Books – The R Book – Etc. List serve ?function

15
Useful Packages...for us Statistical – VEGAN – lme4 – gam – nnet – Rcmdr Graphical – lattice – Rcmdr – gplots Data management – RODBC – doBy – reshape

16
Possibilities... Customized graphics... Complex statistics...

17
t-test ANOVA Simple Linear Regression Multiple Linear Regression ANCOVA GENERAL LINEAR MODELS ε ~ Normal R: lm()

18
t-test ANOVA Simple Linear Regression Multiple Linear Regression ANCOVA Poisson Binomial Negative Binomial Gamma Multinomial GENERALIZED LINEAR MODELS Inverse Gaussian Exponential GENERAL LINEAR MODELS ε ~ Normal Linear combination of parameters R: lm() R: glm()

19
t-test ANOVA Simple Linear Regression Multiple Linear Regression ANCOVA Poisson Binomial Negative Binomial Gamma Multinomial GENERALIZED LINEAR MODELS Inverse Gaussian Exponential Non-linear effect of covariates GENERALIZED ADDITIVE MODELS GENERAL LINEAR MODELS ε ~ Normal Linear combination of parameters R: lm() R: glm() R: gam()

20
Fixed effects modelRandom effects model

Similar presentations

OK

Statistics package Graphics package Programming language Can be used to share/reproduce analyses Many new packages being created - can be downloaded.

Statistics package Graphics package Programming language Can be used to share/reproduce analyses Many new packages being created - can be downloaded.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Download ppt on bhuj earthquake 2001 Ppt on acid-base titration problems Ppt online exam form 2014 Ppt on market friendly states Ppt on personal health record in cloud computing Ppt on natural resources and conservation service Laser video display ppt on ipad Ppt on agriculture in india 2013 Ppt on event management company Ppt on power diode pdf