Primitive data types

Data type | Example ------------- | ------------- Integer | 1 Logical | TRUE Numeric | 1.1 String / character | "Red" Factor (enumerated string) | "Amber" or 2 in c("Red","Amber","Green") Complex | i Date | "2015-04-24"

Compound data types

Data type | Info | Construction example(s) ------------- | ------------- | ------------- Vector | A 1D set of values of the same data type | c(1,"a") , 1:3 , LETTERS Matrix | A 2D set of values of the same data type | matrix(LETTERS,nrow=13, ncol=2) , rbind(1:5,2:6) Array | An nD set of values of the same data type | array(LETTERS, c(13,2)) Data.frame | A 2D set of values of different data types | data.frame(a=1:26, b=LETTERS) List | A collection of objects of various data types | list(vector=c(1,"a"), df=data.frame(a=1:6)) Classes | A class is like a formalised list and can also contain functions i.e. methods | Won't be covered in this class

NB: Most of my work uses vectors, data.tables (a souped up version of data.frames), and lists

Useful functions relating to data types

Function | Use ------------- | ------------- is.[data type] | Whether a vector is of a particular type as.[data type] | Attempts to coerce a vector to a data type str | Structure of an object including class/data type, dimensions class | The class(es)/data type(s) an object belongs to summary | Summarises an object dput | Get R code that recreates an object unlist | Simplify a list to a vector dim | Dimensions of a data type



stephlocke/Rtraining documentation built on May 30, 2019, 3:36 p.m.