How do I insert scales in my geom_area graphic?

Question

I'm coding a graphic and I'm giving the scales Y that I want to plot, but when I plot it the scales is wrong. See it:

ggplot(pop_idade_escolar_americana, aes(x = Ano, y = De.0a5.anos)) +
  geom_area( fill="#69b3a2", alpha=0.4) +
  geom_line(color="#69b3a2", size=2) +
  geom_point(size=3, color="#69b3a2") +
  scale_y_continuous(breaks = c(10000, 11000, 13000, 14000),
                     labels = comma_format(big.mark = ".")) +
  labs(y = NULL,
       x = NULL) +
  hrbrthemes::theme_ipsum()

Plot:

Answer 1

Use geom_ribbon instead of geom_area.

The only differences between the two:

geom	Required aesthetics	Defaults
geom_ribbon	x, ymin, ymax	(none)
geom_area	x, y	ymin=0 (and ymax=y)

ggplot(pop_idade_escolar_americana, aes(x = Ano, y = De.0a5.anos)) +
  geom_ribbon(aes(ymin = -Inf, ymax = De.0a5.anos), fill="#69b3a2", alpha=0.4) +
  geom_line(color="#69b3a2", size=2) +
  geom_point(size=3, color="#69b3a2") +
  scale_y_continuous(breaks = c(10000, 11000, 13000, 14000),
                     labels = comma_format(big.mark = ".")) +
  labs(y = NULL,
       x = NULL) +
  hrbrthemes::theme_ipsum()

The use of ymin = -Inf uses ggplot's default expansion of the axis, so it'll be "a little" below the minimum observed value. Some alternatives for defining ymin:

• literal ymin = 9000 (may be inside or outside aes(..))
• manual offset ymin = min(De.0a5.anos) - 500 (must be inside aes(..)), the offset may be nothing (just min(..)) if you desire