在ggplot2中格式化季度日期

Question

我有这张图：（厄瓜多尔的实际 GDP 周期）

这是构建它的代码：

df %>%
 filter(Serie %in% "GDP Cycle") %>%
 ggplot() +
 aes(x = quarters, y = Valor) +
 geom_line(size = 1L, colour = "#cb181d") +
 labs(x = "Trimestres", y = "% Standard Deviation from Trend", title = "Ciclo del PIB Real del Ecuador", subtitle = "Corte trimestral, Año Base 2007", caption = "Banco Central del Ecuador") +
 theme_light()+ theme(plot.title = element_text(face = "bold", size = 15))+ theme(plot.subtitle = element_text(size = 10))+
  geom_hline(yintercept = 0,linetype="dashed", size=1)

如何在 X 轴上显示每个季度的标签，如下所示：

2000.q1, 2000.q2, . . ., 2020.q1, 2020.q2, 2020.q3

这是数据示例：

df %>%
+     filter(Serie %in% "GDP Cycle")
# A tibble: 83 x 4
   counter quarters            Serie         Valor
     <dbl> <dttm>              <chr>         <dbl>
 1       1 2000-01-01 00:00:00 GDP Cycle -0.00973 
 2       2 2000-04-01 00:00:00 GDP Cycle -0.000653
 3       3 2000-07-01 00:00:00 GDP Cycle  0.0125  
 4       4 2000-10-01 00:00:00 GDP Cycle  0.0195  
 5       5 2001-01-01 00:00:00 GDP Cycle  0.00608 
 6       6 2001-04-01 00:00:00 GDP Cycle  0.00562 
 7       7 2001-07-01 00:00:00 GDP Cycle -0.00471 
 8       8 2001-10-01 00:00:00 GDP Cycle -0.00357 
 9       9 2002-01-01 00:00:00 GDP Cycle -0.00137 
10      10 2002-04-01 00:00:00 GDP Cycle  0.00144 
# … with 73 more rows

如何以这种格式获取 x 轴上的标签：“Jan 2000”到“Jul 2020”？

Answer 1

由于quarters 是POSIXct 类型，您可以使用scale_x_datetime 并指定要显示x 轴值的格式和中断。

按月格式获取 x 轴上的标签：（“Jan 2000”到“Jul 2020”）

library(dplyr)
library(zoo)
library(zoo)

df %>%
  filter(Serie %in% "GDPCycle") %>%
  ggplot() +
  aes(x = quarters, y = Valor) +
  geom_line(size = 1L, colour = "#cb181d") +
  labs(x = "Trimestres", y = "% Standard Deviation from Trend", 
       title = "Ciclo del PIB Real del Ecuador", 
       subtitle = "Corte trimestral, Año Base 2007", 
       caption = "Banco Central del Ecuador") +
  theme_light()+ theme(plot.title = element_text(face = "bold", size = 15))+ 
  theme(plot.subtitle = element_text(size = 10))+
  geom_hline(yintercept = 0,linetype="dashed", size=1) +
  scale_x_datetime(date_labels = '%b %Y', date_breaks = '6 months')

要获取每个季度的 X 轴标签，例如 2000.q1、2000.q2，您可以将 POSIXct 时间转换为 yearqtr，然后使用scale_x_yearqtr。

df %>%
  filter(Serie %in% "GDPCycle") %>%
  mutate(quarters = as.yearqtr(quarters)) %>%
  ggplot() +
  aes(x = quarters, y = Valor) +
  geom_line(size = 1L, colour = "#cb181d") +
  labs(x = "Trimestres", y = "% Standard Deviation from Trend", 
       title = "Ciclo del PIB Real del Ecuador", 
       subtitle = "Corte trimestral, Año Base 2007", 
       caption = "Banco Central del Ecuador") +
  theme_light()+ theme(plot.title = element_text(face = "bold", size = 15))+ 
  theme(plot.subtitle = element_text(size = 10))+
  geom_hline(yintercept = 0,linetype="dashed", size=1) +
  scale_x_yearqtr(format = '%Y.q%q')

Answer 2

您可以使用scale_x_datetime 指定x 轴，并使用zoo::format.yearqtr 进行一些自定义以使格式正确。

library(zoo)
ggplot(df, aes(x = quarters, y = Valor)) +
  geom_line(size = 1L, colour = "#cb181d") +
  geom_hline(yintercept = 0,linetype="dashed", size=1) +
  scale_x_datetime(labels = function(x) zoo::format.yearqtr(x, "%Y.q%q")) + 
  labs(x = "Trimestres", y = "% Standard Deviation from Trend",
       title = "Ciclo del PIB Real del Ecuador",
       subtitle = "Corte trimestral, Año Base 2007",
       caption = "Banco Central del Ecuador") +
  theme_light() + 
  theme(plot.title = element_text(face = "bold", size = 15),
        plot.subtitle = element_text(size = 10))