使用 R 中的 ggplot package 更改 x 轴和 y 轴间距

Question

I am making a graph in ggplot, but I cannot improve the visualization of the abscissa and ordinates.

In the abscissa (X) the years are very close and in the ordinate I would like to stretch vertically a little more. What arguments can I add to the code to improve it?

follow my code and the result of it:

IQA_total<-quali3%>%
  select(Estacao, Ano2, IQA)


ggplot(IQA_total, aes(x=Ano2, y=IQA, group = 1)) +
  geom_point() +
  geom_line(color="steelblue") +
  scale_x_date(breaks = '1 years', date_labels = '%Y') +
  facet_wrap(~Estacao) +
  labs(subtitle = "Mean Annual IQA",
       x = "Year",
       y = "Mean IQA") +
  theme_bw(6)+
  theme_minimal() +
  theme(text = element_text(size = 8))+
  theme(axis.text.x = element_text(angle = 90))

chart result

Edit update

I try scales="free", but the result no well

enter image description here

update 2

dput(head(IQA_total))

structure(list(Dist_Foz = c("334", "334", "0", "0", "0", "0"), 
    Altitude = c("173", "173", "143", "143", "143", "143"), Classe = c("2", 
    "2", "2", "2", "2", "2"), Ano = c(2018, 2018, 2005, 2005, 
    2005, 2005), Estacao = c("00MS023AQ2334", "00MS023AQ2334", 
    "00MS23AC2000", "00MS23AC2000", "00MS23AC2000", "00MS23AC2000"
    ), Ano2 = structure(c(17532, 17897, 12784, 12784, 13149, 
    13149), class = "Date"), IQA = c(77, 78, 50, 49, 61, 38)), row.names = c(NA, 
-6L), groups = structure(list(Estacao = c("00MS023AQ2334", "00MS023AQ2334", 
"00MS23AC2000", "00MS23AC2000"), Dist_Foz = c("334", "334", "0", 
"0"), Altitude = c("173", "173", "143", "143"), Classe = c("2", 
"2", "2", "2"), Ano = c(2018, 2018, 2005, 2005), Ano2 = structure(c(17532, 
17897, 12784, 13149), class = "Date"), .rows = structure(list(
    1L, 2L, 3:4, 5:6), ptype = integer(0), class = c("vctrs_list_of", 
"vctrs_vctr", "list"))), row.names = c(NA, 4L), class = c("tbl_df", 
"tbl", "data.frame"), .drop = TRUE), class = c("grouped_df", 
"tbl_df", "tbl", "data.frame"))

Answer 1

Try this as r2Evans points out with 2 years breaks

IQA_total<-quali3%>%
  select(Estacao, Ano2, IQA)


ggplot(IQA_total, aes(x=Ano2, y=IQA, group = 1)) +
  geom_point() +
  geom_line(color="steelblue") +
  scale_x_date(breaks = '2 years', date_labels = '%Y') +
  facet_wrap(~Estacao) +
  labs(subtitle = "Mean Annual IQA",
       x = "Year",
       y = "Mean IQA") +
  theme_bw(6)+
  theme_minimal() +
  theme(text = element_text(size = 8))+
  theme(axis.text.x = element_text(angle = 90))