R Script

Introduction and Practice -1

Shawn Chen  2016.8.13

R語言簡介

面對撲面而來的資料浪潮，包含 Google、Facebook、Intel、Pfizer、Bank of America 等國際級企業，都已經採用 R 語言進行資料分析，許多全球一流大學如 Stanford、Johns Hopkins 和 UCLA 也將 R 視為資料分析課程的先修科目。R 語言具有免費、跨平台、佔有率高、可塑性高等優勢，各式各樣的 R 社群蓬勃發展。在國際知名的 KDnuggets 論壇統計當中，R 語言已經連續三年獲得資料科學家最常使用的資料分析語言第一名。

IEEE Spectrum Rank

Let's try it!

If you do not finish RStudio downloading, use this link.

RStudio Interface

Try it!

> x <- 10
> y <- "IBM"
>

Try it!

> x <- 10
> y <- "IBM"
> z <- rnorm(1000, mean = 100, sd = 5)
>

rnorm?

> z <- rnorm(1000, mean = 100, sd = 5)
> ?rnorm
>

rnorm

> z <- rnorm(1000, mean = 100, sd = 5)
> ?rnorm
> z

rnorm

> z <- rnorm(1000, mean = 100, sd = 5)
> ?rnorm
> z
> hist(z)
>

Exercise 1

Display the histogram of normal distribution with 1000 numbers, average 10 and standard deviation 10

Exercise 1

> hist(rnorm(1000, mean = 10, sd = 10))
> 

R Data Structure

R's Basic Data Types

• Integer
• Numeric
• Complex
• Character
• Logical

Data Types

> class(x)
[1] "numeric"
> class(y)
[1] "character"
>

Data Types

> class(x)
[1] "numeric"
> class(z)
[1] "numeric"
> class(z)
[1] "numeric"
> 

Data Types

> x <- 10
> class(x)
[1] "numeric"
> x <- as.integer(x)
> class(x)
[1] "integer"
> 

Data Types

> x <- 10
> class(x)
[1] "numeric"
> x <- as.integer(x)
> class(x)
[1] "integer"
> y <- as.integer(y)
Warning message:
NAs introduced by coercion 

General Data Structures

• Vector
• Matrix
• Array
• List
• Data Frame

Vector

The basic data object in R,

consisting of one or more values of

a single data type.

Matrix

A two-dimensional of a single data type.

Array

A multi-dimensional object of a single data type.

Data Frame

A special kind of named list where all elements has the same length.

List

A list can contain (multi) dimensional objects of any data type.

Vector

Matrix

Array

DataFrame

List

Practice

Create Vector

> V <- c(10, 5, 3, 1, 0)
> class(V)
[1] "numeric"
> 

Create Vector

> V <- c(10, 5, 3, 1, 0)
> class(V)
[1] "numeric"
> V <- as.integer(V)
> class(V)
[1] "integer"
> 

Create Vector

> V2 <- c(1, 2, NA, NA, 5)
> V2[1]
[1] 1
> V2[4]
[1] NA
> 

Create Vector

> V3 <- 1:10
> V3
 [1]  1  2  3  4  5  6  7  8  9 10
> 

Exercise2