Formatting quarterly dates in ggplot2

Question

I have this graph:(Real GDP cycle of Ecuador)

This is the code that had built it:

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)

How can I get that in the X axis show me the labels of each quarter like this:

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

This is an example of the data:

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

How can I make to get the labels on x axis in this format: "Jan 2000" to "Jul 2020"?

Maybe this question/answer: https://stackoverflow.com/questions/51433522/convert-yyyy-mm-dd-to-yyyy-yy-qx-in-r — Dave2e, Jan 27 '21 at 03:44

score 3 · Accepted Answer · answered Jan 27 '21 at 03:53

Since quarters is of type POSIXct you can use scale_x_datetime and specify the format and breaks in which you want to show the x-axis value.

To get the labels on x axis in monthly format: ("Jan 2000" to "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')

To get labels on X-axis for each quarter like this 2000.q1, 2000.q2, you can convert POSIXct time to yearqtr and then use 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')

You Genius! In the second graph how can I change from 2000.q1 to 2000.t1 Because in spanish quarter is "trimestre" (three months) — Jorge Paredes, Jan 28 '21 at 03:38
You can change the last line to `scale_x_yearqtr(format = '%Y.t%q')` — Ronak Shah, Jan 28 '21 at 03:40
Something strange happened, literally copied and pasted the code and then there was no red line. — Jorge Paredes, Jan 28 '21 at 03:43
A little question! How can I expand the "breaks" on the x axis? I want more breaks — Jorge Paredes, Jan 28 '21 at 04:10
If you want more breaks for `scale_x_yearqtr` you need to specify `n` value like this : `scale_x_yearqtr(format = '%Y.q%q', n = 9)` — Ronak Shah, Jan 28 '21 at 04:20

score 2 · Answer 2 · answered Jan 27 '21 at 03:54

You might specify the x axis with scale_x_datetime and use zoo::format.yearqtr with some customization to get the formatting just right.

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))

`scale_x_datetime` accepts an argument of `breaks = "3 months"` or `breaks = "12 months"`. It defaults to `"6 months"`. — Ian Campbell, Jan 28 '21 at 04:15

Formatting quarterly dates in ggplot2

2 Answers2