Change axes X and Y graphs ggplot in R

Question

I would like to leave the graph in the ggplot so that the y-axis scale, is in millions of tons, so that the values become smaller, and also in the x-axis, appears every month and year.

I used this code to run the graph

Data=seq(as.Date("2018-01-01"), by="1 month", length.out=18)

PAbr=cbind(Data,PAbr)

ggplot(data = PAbr, aes(x = Data, y = Produção)) +

  geom_line(size=1)+ 

  scale_x_date(date_labels = "%b/%Y") + theme_minimal()

And my database is billions of tons of data, so the data doesn’t appear whole on the y-axis, the way I’d like it, so the idea of changing the scale.

If anyone can help me, I’d appreciate it.

Answer 1

# Dados de exemplo
set.seed(123)
PAbr <- data.frame(
  Data = seq(as.Date("2018-01-01"), by = "1 month", length.out = 18),
  Produção = rnorm(18, 10^9, 10^8) )

library(ggplot2)

ggplot(PAbr, aes(Data, Produção/10^9)) +
  geom_line(size = 1) + 
  scale_x_date(NULL, date_labels = "%b/%y", date_breaks = "1 month") +
  scale_y_continuous("Produção (em milhões de toneladas)") +
  theme_minimal()

Answer 2

Just giving another option using the great example of Carlos. If you want something more complicated/different changing the axes you can use the package scales, which is what the ggplot uses to create the axes.
Here I create a function transf_eixo which specifies that the axis will be transformed into 1e-9, rounded to the first decimal place and comma as separator. And then I apply the function to the y-axis.
The function and the package have more options and formats to work with, so they give more power to leave the axes as you want.

# Dados de exemplo de Carlos
set.seed(123)
PAbr <- data.frame(
  Data = seq(as.Date("2018-01-01"), by = "1 month", length.out = 18),
  Produção = rnorm(18, 10^9, 10^8) )

library(ggplot2)
library(scales)

transf_eixo <- number_format(scale = 1e-9, accuracy = .1, decimal.mark = ",")

ggplot(PAbr, aes(Data, Produção)) +
  geom_line(size = 1) + 
  scale_x_date(NULL, date_labels = "%b/%y", date_breaks = "1 month") +
  scale_y_continuous(name = "Produção (em milhões de toneladas)",
                     labels = transf_eixo) +
  theme_minimal()

Answer 3

Try to use this

p1 + scale_y_continuous(breaks = c(2, 4, 6))

Break are the scales, try to put manually.