stacked bar plot with ggplot

Question

I\'m trying to make a stacked bar plot with the following dataframe:

 totalleft
        1S 2S 3S 4S 12S 25S      tests
A-000   5  0 10 10   0  NA       A-000
A-0         


        

Answer 1

So you need to reshape the data. You want a stacked barplot, so you will need to tell ggplot about variables 1S, 2S ... and tests.

#let's melt the data
#library(reshape2)
data.plot.m <-melt(data.plot, id.vars = "tests") #I stored your data in data.plot
data.plot.m$variable <-gsub("X","",data.plot.m$variable) 
#as R doesn't like variable names beginning with numbers,
#it adds an 'X' automatically when
#we load the data with read.table so we remove this from melted data

#now we plot the data
ggplot(data.plot.m,aes(y = value,x = variable,fill = tests)) +
geom_bar(stat = "identity")

You will notice the order of the plots are different. We will need to reorder your variable:

data.plot.m$variable <- factor(data.plot.m$variable, levels = unique(data.plot.m$variable))
#now plot again
ggplot(data.plot.m,aes(y = value,x = variable,fill = tests))+
geom_bar(stat = "identity") 

I just realized you wanted this instead

ggplot(data.plot.m,aes(y=value,x=tests,fill=variable))+geom_bar(stat="identity")

and with the x-axis tick labels rotated

ggplot(data.plot.m,aes(y=value,x=tests,fill=variable))+geom_bar(stat="identity") + theme(axis.text.x = element_text(angle=90))

Note how I switched x and fill