ggplot2中scale_x_datetime的意外行为 [英] Unexpected behavior of scale_x_datetime in ggplot2

问题描述

我有以下每日收集数据的数据集。

  R> toydata 
日期组系数
 1 2011-11-04 23:59:59 1 2.32 
 2 2011-11-05 23:59:59 1 2.34 
 3 2011-11 -06 23:59:59 1 2.46 
 4 2011-11-07 23:59:59 1 2.68 
 5 2011-11-04 23:59:59 2 2.17 
 6 2011- 11-05 23:59:59 2 1.90 
 7 2011-11-06 23:59:59 2 2.13 
 8 2011-11-07 23:59:59 2 2.52 
  

所有东西似乎都可以正常工作：

  R> toydata $ date 
 [1]2011-11-04 23:59:59 EST2011-11-05 23:59:59 EST
 [3]2011-11-06 23 ：59：59 EST2011-11-07 23:59:59 EST
 [5]2011-11-04 23:59:59 EST2011-11-05 23:59:59 EST
 [7]2011-11-06 23:59:59 EST2011-11-07 23:59:59 EST
  

和

  R>格式（toydata $ date，％d-％b）
 [1]04-Nov05-Nov06-Nov07-Nov04-Nov05-Nov 06-Nov07-Nov
  

但是，当我尝试使用ggplot2使用以下代码

  R> p <-ggplot（toydata，aes（x = date，y = coef，group = group））
 R> pq <-p + geom_line（aes（color = group））+ 
 + scale_x_datetime（major =1 day，format =％d-％b）
  
 
 
 
我收到了意想不到的结果： 
 
 
  
 
 
 
正如你所看到的，11月6日是重复的。我可以通过将x中的标签视为字符串而不是日期来解决此问题，但我很好奇为什么会发生这种情况。我错过了明显的东西吗？ 
解决方案
只需指定 tz ='EST' 。无论默认情况是重复11月6日，因为夏令时开关。
 
I have the following dataset with daily collected data.
R> toydata
                 date group coef
1 2011-11-04 23:59:59     1 2.32
2 2011-11-05 23:59:59     1 2.34
3 2011-11-06 23:59:59     1 2.46
4 2011-11-07 23:59:59     1 2.68
5 2011-11-04 23:59:59     2 2.17
6 2011-11-05 23:59:59     2 1.90
7 2011-11-06 23:59:59     2 2.13
8 2011-11-07 23:59:59     2 2.52
Everythings seems to work fine:
R> toydata$date
[1] "2011-11-04 23:59:59 EST" "2011-11-05 23:59:59 EST"
[3] "2011-11-06 23:59:59 EST" "2011-11-07 23:59:59 EST"
[5] "2011-11-04 23:59:59 EST" "2011-11-05 23:59:59 EST"
[7] "2011-11-06 23:59:59 EST" "2011-11-07 23:59:59 EST"
and 
R> format(toydata$date, "%d-%b")
[1] "04-Nov" "05-Nov" "06-Nov" "07-Nov" "04-Nov" "05-Nov" "06-Nov" "07-Nov"
However, when I try to plot it using ggplot2 using the following code 
R> p <- ggplot(toydata, aes(x = date, y = coef, group = group))
R> pq <- p + geom_line(aes(colour = group)) +
+   scale_x_datetime(major = "1 day", format = "%d-%b")
I get an unexpected result:



As you can see, November, 6 is duplicated. I can get around this problem by just treating the labels in x as strings and not as dates, but I am curious about why this is happening. Am I missing something obvious? 
解决方案
Just specify tz='EST' and it works for me. Whatever the default is is repeating Nov 6 because of the daylight savings time switch.

                        
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