ggplot Time Series Figure Error: Invalid input: time_trans works with objects of class POSIXct only BUT data is in POSIXct

Question

我的数据集是一个包含过去 4 个夏天每日最高水温的数据框。

     X site      DateTime            value Month Year  Day  
   <int> <fct>     <dttm>              <dbl> <int> <fct> <chr>
 1  6775 RAYNER_UP 2018-07-09 19:00:00  19.8     7 2018  07/10
 2  6776 RAYNER_UP 2018-07-10 19:00:00  21.2     7 2018  07/11
 3  6777 RAYNER_UP 2018-07-11 19:00:00  20.4     7 2018  07/12
 4  6778 RAYNER_UP 2018-07-12 19:00:00  20.1     7 2018  07/13
 5  6779 RAYNER_UP 2018-07-13 19:00:00  17.3     7 2018  07/14
 6  6780 RAYNER_UP 2018-07-14 19:00:00  19.5     7 2018  07/15
 7  6781 RAYNER_UP 2018-07-15 19:00:00  21.2     7 2018  07/16
 8  6782 RAYNER_UP 2018-07-16 19:00:00  21.0     7 2018  07/17
 9  6783 RAYNER_UP 2018-07-17 19:00:00  19.8     7 2018  07/18
10  6784 RAYNER_UP 2018-07-18 19:00:00  16.8     7 2018  07/19

我的目标是制作一个折线图，每年都有不同的线。到目前为止，在互联网的大量帮助下，我每年都做了一个线，但是规模非常拥挤example。

我想重新调整我的时间序列中的 x 轴以显示一个月中的几天。

到目前为止在 ggplot 中使用 scale_x_datetime 和 scale_x_date 但没有成功。我不断收到错误消息：无效输入：time_trans 仅适用于 class POSIXct 的对象，即使日期列在 POSIXct 中也是如此。

给出问题的代码示例：

test1 = ggplot() +
geom_line(data = Rayner_up_summer, aes(x=strftime(DateTime,format="%m/%d"),
                                  y=value, 
                                group = Year,
                                  color=strftime(DateTime,format="%Y")))+
                               # size=.1))+
 scale_color_discrete(name="Year")+
 labs(x="date")

有谁知道为什么我无法使用 scale_x_datetime 即使我的 x 轴 (DateTime) 是 POSIXct 日期时间格式？如果您有任何建议，我将不胜感激

Answer 1

正如我在评论中所说，问题是您通过 strftime(DateTime,format="%m/%d") 将 DateTime 列转换为一个字符，这就是为什么您的秤非常拥挤的原因，也是为什么scale_x_date 或 _datetime 将不起作用。

相反，实现您想要的结果的一种选择是

在您使用同一年份的数据中添加辅助日期列。
将此帮助日期列映射到 x

注意：我稍微修改了你的数据集以说明第二年。

Rayner_up_summer$DateTime <- as.Date(paste0("2018/", Rayner_up_summer$Day))

library(ggplot2)

ggplot() +
  geom_line(data = Rayner_up_summer, aes(
    x = DateTime,
    y = value,
    group = Year,
    color = factor(Year)
  )) +
  scale_x_date(date_labels = "%m/%d") +
  scale_color_discrete(name = "Year") +
  labs(x = "date")

数据

Rayner_up_summer <- structure(list(X = c(
  6775L, 6776L, 6777L, 6778L, 6779L, 6780L,
  6781L, 6782L, 6783L, 6784L, 6775L, 6776L, 6777L, 6778L, 6779L,
  6780L, 6781L, 6782L, 6783L, 6784L
), site = c(
  "RAYNER_UP", "RAYNER_UP",
  "RAYNER_UP", "RAYNER_UP", "RAYNER_UP", "RAYNER_UP", "RAYNER_UP",
  "RAYNER_UP", "RAYNER_UP", "RAYNER_UP", "RAYNER_UP", "RAYNER_UP",
  "RAYNER_UP", "RAYNER_UP", "RAYNER_UP", "RAYNER_UP", "RAYNER_UP",
  "RAYNER_UP", "RAYNER_UP", "RAYNER_UP"
), DateTime = structure(c(
  1531173600,
  1531260000, 1531346400, 1531432800, 1531519200, 1531605600, 1531692000,
  1531778400, 1531864800, 1531951200, 1531173600, 1531260000, 1531346400,
  1531432800, 1531519200, 1531605600, 1531692000, 1531778400, 1531864800,
  1531951200
), class = c("POSIXct", "POSIXt"), tzone = ""), value = c(
  19.8,
  21.2, 20.4, 20.1, 17.3, 19.5, 21.2, 21, 19.8, 16.8, 21.5740302174818,
  21.6853770664893, 18.4306976739317, 21.1522381303366, 20.208727594465,
  19.5954797456507, 20.6829415732063, 17.6733329861891, 20.2849614520092,
  20.5253239201847
), Month = c(
  7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L,
  7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 7L
), Year = c(
  2018,
  2018, 2018, 2018, 2018, 2018, 2018, 2018, 2018, 2018, 2019, 2019,
  2019, 2019, 2019, 2019, 2019, 2019, 2019, 2019
), Day = c(
  "07/10",
  "07/11", "07/12", "07/13", "07/14", "07/15", "07/16", "07/17",
  "07/18", "07/19", "07/10", "07/11", "07/12", "07/13", "07/14",
  "07/15", "07/16", "07/17", "07/18", "07/19"
)), row.names = c(
  "1",
  "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "21", "31",
  "41", "51", "61", "71", "81", "91", "101"
), class = "data.frame")

ggplot Time Series Figure Error: Invalid input: time_trans works with objects of class POSIXct only BUT data is in POSIXct

ggplot Time Series Figure Error: Invalid input: time_trans works with objects of class POSIXct only BUT data is in POSIXct

r

ggplot2

posixct