(R)The way to make "Stacked Area Graph" / The way to switch the order of legend and stack/geom_area()

<geom_area() - stacked area graph>

<The first example> 

> data_frame_1<-data.frame(Year=c(2008,2008,2010,2010,2012,2012,2014,2014,2016,2016,2018,2018,2020,2020),Sex=c("F","M","F","M","F","M","F","M","F","M","F","M","F","M"),Freshmen=c(73,62,79,64,82,70,90,83,103,94,140,125,165,143))

> View(data_frame_1)

> ggplot(data=data_frame_1,aes(x=Year,y=Freshmen,fill=Sex))+geom_area()	> ggplot(data=data_frame_1,aes(x=factor(Year),y=Freshmen,fill=Sex,group=Sex)) +geom_area()
elements of Year in the graph is 2007.5, 2010.0 ... difficult to decode the graph.	elements of factor(Year) in the graph is 2008,2010,2012,2014,2016,2018,2020

<The second example>

> data_frame_2<-data.frame(Year=c(2008,2008,2008,2008,2010,2010,2010,2010,2012,2012,2012,2012,2014,2014,2014,2014,2016,2016,2016,2016,2018,2018,2018,2018,2020,2020,2020,2020),Age=c(18,19,20,21,18,19,20,21,18,19,20,21,18,19,20,21,18,19,20,21,18,19,20,21,18,19,20,21),freshmen=c(13,37,46,15,18,39,40,12,25,47,56,17,23,59,73,24,28,78,92,30,33,92,100,32,42,130,140,42))

>View(data_frame_2)

> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age))+geom_area()

> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age))+geom_area(colour="black")

> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age))+geom_area(colour="black",alpha=0.6)

<A way to set stacked order & legend order by yourself>

>  data_frame_2$Age<- factor(data_frame_2$Age,level=c(18,19,20,21)) > ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age)) +geom_area(colour="black",alpha=0.6)	> data_frame_2$Age<-factor(data_frame_2$Age,level=c(21,20,19,18)) > ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age)) +geom_area(colour="black",alpha=0.6)

<Swith the order of legend>

>data_frame_2$Age<-factor(data_frame_2$Age)

> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age)) +geom_area(colour="black",alpha=0.4)+scale_fill_brewer(palette=1)	> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age)) +geom_area(colour="black",alpha=0.4) +scale_fill_brewer(palette=1,breaks=rev(data_frame_2$Age))

<Swith the stacked order>

> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age)) +geom_area(colour="black",alpha=0.4)+scale_fill_brewer(palette=1)	> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age)) +geom_area(position=position_stack(reverse=TRUE),colour="black",alpha=0.4) +scale_fill_brewer(palette=1)

<Swith both the legend order and stacked order>

> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age)) +geom_area(colour="black",alpha=0.4) +scale_fill_brewer(palette=1)	> ggplot(data=data_frame_2,aes(x=factor(Year),y=freshmen,fill=Age,group=Age)) +geom_area(position=position_stack(reverse=TRUE),colour="black",alpha=0.4) +scale_fill_brewer(palette=1,breaks=rev(levels(data_frame_2$Age)))

<Proportional stacked area graph - way1 > 

>library(plyr)

> data_frame_3<-ddply(data_frame_2,"Year", transform, freshper=freshmen/sum(freshmen)*100)

> View(data_frame_3)

> ggplot(data_frame_3,aes(x=factor(Year),y=freshper,fill=Age,group=Age))+geom_area(colour="black",alpha=0.6)+scale_fill_brewer(palette=1)

<Proportional stacked area graph - way2 > 

> data_frame_3<-data_frame_2%>%group_by(Year)%>%mutate(sum_freshmen=sum(freshmen))

> View(data_frame_3)

> data_frame_3<-data_frame_2%>%group_by(Year)%>%mutate(sum_freshmen=sum(freshmen),pro_freshmen=freshmen/sum(freshmen)*100)

>View(data_frame_3)

>ggplot(data=data_frame_3,aes(x=factor(Year),y=pro_freshmen,fill=Age,group=Age))+geom_area(colour="black",alpha=0.6)+scale_fill_brewer(palette=1)

Way1	Way2
> data_frame_3<-ddply(data_frame_2,"Year", transform,freshper=freshmen/sum(freshmen)*100)   > ggplot(data_frame_3,aes(x=factor(Year),y=freshper,fill=Age,group=Age)) +geom_area(colour="black",alpha=0.6)+scale_fill_brewer(palette=1)	> data_frame_3<-data_frame_2%>%group_by(Year) %>%mutate(pro_freshmen=freshmen/sum(freshmen)*100) >ggplot(data=data_frame_3,aes(x=factor(Year),y=pro_freshmen,fill=Age,group=Age)) +geom_area(colour="black",alpha=0.6)+scale_fill_brewer(palette=1)