AS1

1. 敘述統計

1.1 讀檔

Oilprice <- read.csv("oilprice1.csv")
summary(Oilprice)

##         日期      西德州.美元.桶.  杜拜.美元.桶.    布蘭特.美元.桶. 
##  2000/1/10:   1   Min.   : 17.45   Min.   : 15.90   Min.   : 16.97  
##  2000/1/11:   1   1st Qu.: 38.39   1st Qu.: 34.35   1st Qu.: 38.17  
##  2000/1/12:   1   Median : 59.45   Median : 57.74   Median : 60.22  
##  2000/1/13:   1   Mean   : 62.34   Mean   : 62.24   Mean   : 65.00  
##  2000/1/14:   1   3rd Qu.: 85.79   3rd Qu.: 86.81   3rd Qu.: 91.04  
##  2000/1/15:   1   Max.   :145.49   Max.   :140.70   Max.   :144.52  
##  (Other)  :4789                                                     
##       Year     
##  Min.   :2000  
##  1st Qu.:2004  
##  Median :2009  
##  Mean   :2009  
##  3rd Qu.:2014  
##  Max.   :2018  
## 

colnames(Oilprice) <- c("Date","WestTexas","Dubai","IBCON","YEAR")
str(Oilprice)

## 'data.frame':    4795 obs. of  5 variables:
##  $ Date     : Factor w/ 4795 levels "2000/1/10","2000/1/11",..: 4791 4790 4788 4787 4786 4785 4784 4783 4782 4781 ...
##  $ WestTexas: num  69.8 70.2 69.5 68.5 68.9 ...
##  $ Dubai    : num  75.7 75.7 74.3 75 74.3 ...
##  $ IBCON    : num  77.7 77.8 77.3 75.9 76.3 ...
##  $ YEAR     : int  2018 2018 2018 2018 2018 2018 2018 2018 2018 2018 ...

Oilprice$YEAR <- factor(Oilprice$YEAR)

1.2 單一變數

#2000年-2018年內各地區油價
mean(Oilprice$WestTexas)  #平均數

## [1] 62.34499

sd(Oilprice$WestTexas)    #標準差

## [1] 27.03306

sd(Oilprice$WestTexas)^2  #變異數

## [1] 730.7862

mean(Oilprice$Dubai)      #平均數

## [1] 62.2387

sd(Oilprice$Dubai)        #標準差

## [1] 30.42798

sd(Oilprice$Dubai)^2      #變異數

## [1] 925.8622

mean(Oilprice$IBCON)      #平均數

## [1] 64.99649

sd(Oilprice$IBCON)        #標準差

## [1] 30.90746

sd(Oilprice$IBCON)^2      #變異數

## [1] 955.2711

1.3 箱型圖BoxPlot

installed.packages("ggplot2")

##      Package LibPath Version Priority Depends Imports LinkingTo Suggests
##      Enhances License License_is_FOSS License_restricts_use OS_type Archs
##      MD5sum NeedsCompilation Built

library(ggplot2)

## Warning: package 'ggplot2' was built under R version 3.4.4

#箱型圖Boxplot
#西德州從2000-2018年內油價的變化
boxplot(WestTexas ~ YEAR,
        Oilprice,
        main = " WestTexas's oil price",
        xlab ="Year",
        ylab = "Price",
        col = "grey"
)

#杜拜從2000-2018年內油價的變化
boxplot(Dubai ~ YEAR,
        Oilprice,
        main = " Dubai's oil price",
        xlab ="Year",
        ylab = "Price",
        col = "grey"
)

#倫敦布蘭特原油從2000-2018年內油價的變化
boxplot(IBCON ~ YEAR,
        Oilprice,
        main = " IBCON's oil price",
        xlab ="Year",
        ylab = "Price",
        col = "grey"
)

#各地區油價2000-2018年箱型圖
boxplot(Oilprice$WestTexas,
        main="WestTexas",
        xlab="2000-2018",
        ylab="Price",
        col = "grey")

boxplot(Oilprice$Dubai,
        main="Dubai",
        xlab="2000-2018",
        ylab="Price",
        col = "grey")

boxplot(Oilprice$IBCON,
        main="IBCON",
        xlab="2000-2018",
        ylab="Price",
        col = "grey")

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