How to increase Y-axis scale marks in graphics in ggplot2?

Question

I have a chart with very long scale marks between you, I’d like to increase the amount, but I don’t know how it’s possible.

I would like to increase the number of values in the Y axis, for example, between 32 and 256 and between 2048 and 16384.

Code I am using:

library(tidyverse)
library(gghighlight)

url <- httr::GET("https://xx9p7hp1p7.execute-api.us-east-1.amazonaws.com/prod/PortalGeral",
                 httr::add_headers("X-Parse-Application-Id" =
                                     "unAFkcaNDeXajurGB7LChj8SgQYS2ptm")) %>%
  httr::content() %>%
  '[['("results") %>%
  '[['(1) %>%
  '[['("arquivo") %>%
  '[['("url")

dados <- utils::read.csv2(url, stringsAsFactors = FALSE, fileEncoding = "latin1")
dados$data <- lubridate::as_date(dados$data)

dados <- dados %>%
  filter(data > as.Date("2020-02-29"))

rm(url)

dados %>%
  filter(casosAcumulados > 9) %>%
  group_by(estado) %>%
  mutate(diasposdez = 1:n()) %>%
  ggplot(aes(diasposdez, casosAcumulados)) +
  geom_line(aes(color = estado)) +
  scale_y_continuous(trans = 'log2') +
  labs(x = "Dias depois do 10º caso confirmado", y = "Casos acumulados") +
  gghighlight(estado == c("DF", "SP", "RJ", "AM", "CE")) +
  ggthemes::scale_colour_economist() +
  theme(panel.background = element_rect(fill = "white", colour = "grey10")) +
  theme(panel.grid.major = element_line(colour = "gray", linetype = "dashed"), plot.subtitle = element_text(size = 11))

Answer 1

Use the argument breaks of function scale_y_continous:

dados %>%
    filter(casosAcumulados > 9) %>%
    group_by(estado) %>%
    mutate(diasposdez = 1:n()) %>%
    ggplot(aes(diasposdez, casosAcumulados)) +
    geom_line(aes(color = estado)) +
    scale_y_continuous(trans = 'log2', breaks = 2^(3:15)) +
    labs(x = "Dias depois do 10º caso confirmado", y = "Casos acumulados") +
    gghighlight(estado == c("DF", "SP", "RJ", "AM", "CE")) +
    ggthemes::scale_colour_economist() +
    theme(panel.background = element_rect(fill = "white", colour = "grey10")) +
    theme(panel.grid.major = element_line(colour = "gray", linetype = "dashed"), plot.subtitle = element_text(size = 11))

Any numerical vector can be used to customize the breaks of the y-axis (and thus of the x-axis using the scale_x_continuous).

dados %>%
    filter(casosAcumulados > 9) %>%
    group_by(estado) %>%
    mutate(diasposdez = 1:n()) %>%
    ggplot(aes(diasposdez, casosAcumulados)) +
    geom_line(aes(color = estado)) +
    scale_y_continuous(trans = 'log2', breaks = c(2^(3:8), 2^(11:15))) +
    labs(x = "Dias depois do 10º caso confirmado", y = "Casos acumulados") +
    gghighlight(estado == c("DF", "SP", "RJ", "AM", "CE")) +
    ggthemes::scale_colour_economist() +
    theme(panel.background = element_rect(fill = "white", colour = "grey10")) +
    theme(panel.grid.major = element_line(colour = "gray", linetype = "dashed"), plot.subtitle = element_text(size = 11))