Stacked area chart are often use to represent time series. These examples are inspired from the cookbook for R. Check the dataviz catalog to better understand what is a stacked area graph! Let’s build some data for the next examples:


# ggplot2 library
library(ggplot2)

# DATA
set.seed(345)
Sector <- rep(c("S01","S02","S03","S04","S05","S06","S07"),times=7)
Year <- as.numeric(rep(c("1950","1960","1970","1980","1990","2000","2010"),each=7))
Value <- runif(49, 10, 100)
data <- data.frame(Sector,Year,Value)

# ggplot2 library

library(ggplot2)

# DATA

set.seed(345)

Sector <- rep(c("S01","S02","S03","S04","S05","S06","S07"),times=7)

Year <- as.numeric(rep(c("1950","1960","1970","1980","1990","2000","2010"),each=7))

Value <- runif(49, 10, 100)

data <- data.frame(Sector,Year,Value)

#136_stacked_area_graph_1 This is the basic stacked area plot proposed by ggplot2.


ggplot(data, aes(x=Year, y=Value, fill=Sector)) + 
    geom_area()

ggplot(data, aes(x=Year, y=Value, fill=Sector)) +

geom_area()

#136_stacked_area_graph_2 You can easily change the color palette:


ggplot(data, aes(x=Year, y=Value, fill=Sector)) +
    geom_area(colour="black", size=.2, alpha=.4) +
    scale_fill_brewer(palette="Greens", breaks=rev(levels(data$Sector)))

ggplot(data, aes(x=Year, y=Value, fill=Sector)) +

geom_area(colour="black", size=.2, alpha=.4) +

scale_fill_brewer(palette="Greens", breaks=rev(levels(data$Sector)))

#136_stacked_area_graph_3 To reverse the stacking order, you have to change the order in the initial data frame


data=data[order(data$Sector, decreasing=T) , ]
ggplot(data, aes(x=Year, y=Value, fill=Sector)) +
    geom_area(colour="black", size=.2, alpha=.4) +
    scale_fill_brewer(palette="Greens", breaks=rev(levels(data$Sector)))

data=data[order(data$Sector, decreasing=T) , ]

ggplot(data, aes(x=Year, y=Value, fill=Sector)) +

geom_area(colour="black", size=.2, alpha=.4) +

scale_fill_brewer(palette="Greens", breaks=rev(levels(data$Sector)))

#136_stacked_area_graph_4 Thus you can give a specific order, still reordering the dataframe as needed:


data$Sector=factor(data$Sector , levels=levels(data$Sector)[c(1,4,3,2,7,6,5)])
ggplot(data, aes(x=Year, y=Value, fill=Sector)) + 
    geom_area()

data$Sector=factor(data$Sector , levels=levels(data$Sector)[c(1,4,3,2,7,6,5)])

ggplot(data, aes(x=Year, y=Value, fill=Sector)) +

geom_area()

#136_stacked_area_graph_5 You can also draw a proportional stacked area graph: the sum of each year is always equal to hundred and value of each group is represented through percentages. To make it, you have to calculate these percentages first:


my_fun=function(vec){ as.numeric(vec[3]) / sum(data$Value[data$Year==vec[2]]) *100 }
data$prop=apply(data , 1 , my_fun)

ggplot(data, aes(x=Year, y=prop, fill=Sector)) + 
    geom_area(alpha=0.6 , size=1, colour="black")