以下是資料的基礎統計
summary(polution)
## Country.Code Country.Name year
## AGO : 24 Albania : 24 Min. :1990
## ALB : 24 Algeria : 24 1st Qu.:1996
## ARE : 24 Angola : 24 Median :2002
## ARG : 24 Antigua and Barbuda: 24 Mean :2002
## ATG : 24 Argentina : 24 3rd Qu.:2007
## AUS : 24 Australia : 24 Max. :2013
## (Other):3360 (Other) :3360
## co2_per_GDP GDP_per_capita GDP
## Min. :0.004985 Min. : 242 Min. :8.821e+07
## 1st Qu.:0.137573 1st Qu.: 2180 1st Qu.:7.449e+09
## Median :0.208438 Median : 6361 Median :3.266e+10
## Mean :0.242897 Mean : 12635 Mean :3.522e+11
## 3rd Qu.:0.293970 3rd Qu.: 17440 3rd Qu.:2.260e+11
## Max. :1.420133 Max. :140037 Max. :1.680e+13
##
我們可以發現,2013年人均GDP前十名的地區,在近24年來,CO2/GDP要不下降,要不持平。而人均GDP後十名的地區,則是持平或上升。
polution$year<-as.integer(polution$year)
gdp_per_capita_top10<-head(polution[order(polution$year,polution$GDP_per_capita,decreasing = T),2],n = 10)
gdp_per_capita_low10<-head(polution[polution$year==2013,][order(polution[polution$year==2013,5]),2],n=10)
polution %>%
filter(Country.Name %in% gdp_per_capita_top10) %>%
ggplot(aes(x=year,y=co2_per_GDP))+
geom_line(aes(color=Country.Name))+
geom_point(aes(size=GDP_per_capita,color=Country.Name))+
labs(title="2013年平均每人GDP前十名國家,CO2/GDP變化",x="Year",y="CO2 per GDP")

polution %>%
filter(Country.Name %in% gdp_per_capita_low10) %>%
ggplot(aes(x=year,y=co2_per_GDP))+
geom_line(aes(color=Country.Name))+
geom_point(aes(size=GDP_per_capita,color=Country.Name))+
labs(title="2013年平均每人GDP後十名國家,CO2/GDP變化",x="Year",y="CO2 per GDP")

從1990-2013年對於世界GDP增加貢獻度最高的前十名,中國CO2/GDP大幅下降,其餘者則持平或略有下降。
grow_country<-polution %>%
filter(year %in% c(1990,2013)) %>%
select(Country.Code,Country.Name,year,GDP) %>%
group_by(Country.Code,Country.Name) %>%
summarise(grow_rate=max(GDP)-min(GDP))
gdp_grow_top10<-head(grow_country[order(grow_country$grow_rate,decreasing = T),2],n=10)
gdp_grow_top10<-gdp_grow_top10$Country.Name
polution %>%
filter(Country.Name %in% gdp_grow_top10) %>%
ggplot(aes(x=year,y=co2_per_GDP))+
geom_line(aes(color=Country.Name))+
geom_point(aes(size=GDP,color=Country.Name))+
labs(title="1990-2013年GDP增加量前十名國家,CO2/GDP變化",x="Year",y="CO2 per GDP")

1990年代開始,亞洲四虎快速發展,從圖表中可以看出,在發展初期,CO2/GDP是上升的。
polution %>%
filter(Country.Name %in% c("Philippines","Malaysia","Indonesia","Thailand")) %>%
ggplot(aes(x=year,y=co2_per_GDP))+
geom_line(aes(color=Country.Name))+
geom_point(aes(size=GDP_per_capita,color=Country.Name))+
labs(title="亞洲四虎,CO2/GDP變化",x="Year",y="CO2 per GDP")

從1990-2013年,趨勢線向右下方移動
polution$year<-as.character(polution$year)
polution %>%
filter(year %in% c(1990,2000,2013)) %>%
ggplot(aes(x=GDP_per_capita,y=co2_per_GDP,size=GDP,color=year))+
geom_point()+
coord_cartesian(xlim = c(0,100000),ylim = c(0,1))+
geom_smooth(se = F)+
labs(title="世界各國CO2/GDP比較(1990,2000,2013年)",x="人均GDP",y="CO2 per GDP")
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'
