R Programming Fundamentals
Seq Function
seq(from = 1, to = 1, by = ((to - from) / (length.out - 1)), Unsorted
- getwd() - returns working directory.
- setwd(“E:\STA4502\RCode”) - set the working directory to “E:\STA4502\RCode.
- cbind(x,y) - combine two vectors of same length (x,y) to make a matrix
Our vector will automatically convert our data type if we bind vectors of different data types into a matrix or vector.- data.frame(x,y) - combine two vectors of different types into a dataframe while preserving the original variables’ datatypes. Dataframes can handle different length vectors.
- M = matrix(1:20, nrow = 4, ncol = 5)
- W = list(Matrix, charVector, intVector) - lists can handle basically all types of parameters.
Cleaning
Ctrl + L
- clears the R console
- this does not remove the variables from memory.
- rm(list=ls()) - this will erase the memory.
Var Types
- character
- numeric (real numbers)
- integer
- complex
- logical (True/False)
Vectors
Vectors are the most basic R object. An empty vector may be created with vector().
Vectors may only contain objects of the same class.
Lists, while represented as a vector, can break the rule above and contain objects of different classes.
The c() function can be used to create vectors by concatenating things together.
X = c(2.5, -3.5)Dataframes, Matrices, and Lists
Data frames are standard data objects and are used to combine several variables of the same length and of potentially differing types into a single unit.
D = data.frame(x,y)
D
# x y
# 11 1
# 218 1
# 123 1
# 36 1
# 10 1
Commenting
Commenting is done like python, with #.
# This is a comment. Install Packages
install.package("isdals")Call Data
To see the collection of all datasets in a package.
data(package = "isdals")library() function
library() invisibly returns the list of attached packages.
install.packages("ISLR")
library(ISLR)
data(Hitters)help() function
help() returns a short description of what is included within the data.
help(Hitters)