R graph more questions about parametrization

Question

I have built this graph in R:

library(ggplot2)

dataset <- data.frame(Riserva_Riv_Fine_Periodo = 1:10 * 10^6 + 1,
                      Anno = 1:10)

ggplot(data = dataset, 
            aes(x = Anno, 
                y = Riserva_Riv_Fine_Periodo)) + 
  geom_bar(stat = "identity", 
           width=0.8, 
           position="dodge") + 
  geom_text(aes( y = Riserva_Riv_Fine_Periodo,
            label = round(Riserva_Riv_Fine_Periodo, 0), 
                 angle=90, 
                 hjust=+1.2), 
            col="white", 
            size=4, position = position_dodge(0.9))

As you can see I have 2 issue:

1. the numbers into the bars are truncated.
2. The y scale is written in this format "0e+00"

I'd like to:

1. Set the numbers inside or outside the bar according to the height of the bar
2. Set the y scale in million.

Answer 1

1. You can use an ifelse statement to conditionally change the hjust argument based on the value of the y
2. You can change how R represents decimals using the scipen option.

Here is an example:

library(ggplot2)

options(scipen=2)

dataset <- data.frame(Riserva_Riv_Fine_Periodo = 1:10 * 10^6 + 1,
                      Anno = 1:10)

ggplot(data = dataset, 
            aes(x = Anno, 
                y = Riserva_Riv_Fine_Periodo)) + 
  geom_bar(stat = "identity", 
           width=0.8, 
           position="dodge") + 
  geom_text(aes( y = Riserva_Riv_Fine_Periodo,
                 label = round(Riserva_Riv_Fine_Periodo, 0), 
                 angle=90, 
                 hjust= ifelse(Riserva_Riv_Fine_Periodo < 3000000, -0.1,  1.2)), 
            col="red", 
            size=4, 
            position = position_dodge(0.9))