Learning R hands on

Organization of Folders:

• Class Data folder has datasets (end in .csv or .rda)

• Rcode has the scripts of R commands that can cut and pasted into an R window (end in .R)

• Ppt has the powerpoints

The Basics Rintro.R

• Reading in comma separated data• Listing a data set or its components• Subscripts• Sequences and combing values (: and “c”)• Creating a new data set with <-• Arithmetic in R• Applying some stats to data• Saving your work

Fooling with the data RintroManipulating.R

• Subscripting to get a subset of data • Working with rows and columns• Arithmetic on a column at once

Pay attention to where the commas are!

e.g. BT2[3,5] BT2[3,] BT2[,5] BT2[,3:5] or BT2[1:10,3:5]These are all different!

Plotting DataRintroPlotting.R

• Histogram hist• Adding more features to the plot• Scatterplots using plot• Box plots for several data sets boxplot • Adding text to a scatter plot• Changing the axes scales

Build a complicated plot by adding features through several simple steps

Writing functionsRintroFunctions.R

• The uses for { } and ( ) • What goes in and what comes out• Listing a function• Optional arguments • Calling a function and assigning its results to a new data set • Review of R arithmetic