Question

问题：您对使用ggplot2处理持续时间的建议（作者：Hadley Wickham）。具体来说：复制以下带有自定义间隔和合适标签的图。优先使用自定义功能和/或数据重构的方式最少。欢迎提供我未引用的软件包的建议。

数据以秒为单位存储（请参阅下面的df）。我想显示人眼可读的中断和标签，例如天而不是数千秒，而休息时间是在0、1、2 ...天，而不是尴尬的分数。

工作量证明：下面的第一个示例将持续时间作为整数处理，并通过逐个案例适当地除以60/24/365的倍数等来实现目标。第二个示例使用基数R difftime个对象。为了在这种情况下正确处理，我必须使用strptime函数并减去1。我错过了什么吗？第三个示例使用duration包中的lubridate类。虽然使用day()和seconds_to_period()函数很容易指定标签，但是在设置自定义间隔时我做得不好。第四个示例使用hms类。我设法指定了休息时间，但没有指定标签。也欢迎就以下每个示例提供有关如何编写较短代码行的任何建议。

# Data
df = data.frame(x = 1:6, 
    num = c(374400, 343500, 174000, 193500, 197700, 270300))

# base/difftime
df$difftime <- as.difftime(df$num, units = "secs")

# lubridate/duration
library("lubridate")  # devtools::install_github("tidyverse/lubridate") # the dev version fixes a bug
df$duration <- duration(df$num, units = "seconds")

# hms/hms
library("hms")
df$hms <- as.hms(df$num) 

library("ggplot2")
library("scales")

# 1: data is base/numeric
# Pro: no package dependence
# Con: Hard work 
breaks = seq(0, 100*60*60, 20*60*60)
labels = function(x) round(x/60/60/24, 0)
ggplot(data = df, aes(x = x, y = num)) +
    geom_bar(stat = "identity", fill = "lightblue") +
    scale_y_continuous(name = "Duration (Days)", 
                       breaks = breaks,
                       labels = labels) +
    labs(title = "Data stored as numeric (seconds)", 
         subtitle = "breaks = seq(0, 100*60*60, 20*60*60)\nlabels = function(x) round(x/60/60/24, 0)",
         x = NULL) 
ggsave("base-num.png")

# 2: data is base/difftime
# Pro: simple once you get over the ``strftime(x, "%d")`` syntax.
# Unresolved: Why do I need to subtract a day?
labels = function(x) as.integer(strftime(x, "%d"))-1
ggplot(data = df, aes(x = x, y = difftime)) +
    geom_bar(stat = "identity", fill = "lightblue") +
    scale_y_time(name = "Duration (Days)", 
        labels = labels) +
    labs(title = "Data stored as difftime (seconds)", 
         subtitle = "default breaks\nlabels = function(x) as.integer(strftime(x, '%d'))-1",
         x = NULL) 
ggsave("base-difftime.png")

# 3: data is lubridate/duration
# Pro: intuitive combination of day() and seconds_to_period() functions
# Unresolved: a better way to make own breaks?
breaks = as.duration(seq(0, 5, 1)*60*60*24)
labels = function(x) day(seconds_to_period(x))
ggplot(data = df, aes(x = x, y = duration)) +
    geom_bar(stat = "identity", fill = "lightblue") +
    scale_y_continuous(name = "Duration (Days)", 
        breaks = breaks,
        labels = labels) +
    labs(title = "Data stored as duration (seconds)", 
         subtitle = "breaks = as.duration(seq(0, 5, 1)*60*60*24)\nlabels = function(x)lubridate::day(lubridate::seconds_to_period(x))",
         x = NULL) 
ggsave("lubridate-duration.png")

# 4: data is hms/hms
# Pro: Immediately generates plot with acceptable labels
# Unresolved: how to make own labels:  Failed attempts:
labels = 0:(length(breaks)-1)
labels = function(x)lubridate::day(x)

breaks = seq(0, 5, 1)*60*60*24
ggplot(data = df, aes(x = x, y = hms)) +
    geom_bar(stat = "identity", fill = "lightblue") +
    scale_y_continuous(name = "Duration (Seconds)",
        breaks = breaks) +
    labs(title = "Data stored as hms (seconds)", 
         subtitle = "breaks = seq(0, 5, 1)*60*60*24\ndefault labels",
         x = NULL) 
ggsave("hms-hms.png")

编辑按照Axeman在注释部分的建议，这是将ggplot与hms对象结合的方法。在我看来，这似乎是4中最方便的，尽管必须减去1是出乎意料的。 Axeman，您要发布此答案吗？

breaks = hms::hms(days = 0:4)
labels = function(x) lubridate::day(x)-1

Answer 1

恕我直言，提出的解决方案在我看来过于复杂。

如果持续时间以整数秒为单位，并且需要以天为单位绘制，则我的方法是在对aes()的调用中对其进行缩放：

df = data.frame(x = 1:6, 
                num = c(374400, 343500, 174000, 193500, 197700, 270300))
library("ggplot2")
ggplot(data = df, aes(x = x, y = num / (24*60*60))) +
  geom_col(fill = "lightblue") +
  labs(title = "Data stored as numeric (seconds)",
       y = "Duration (Days)",
       x = NULL)

因此，无需摆弄中断和标签。

NB：geom_col()代替了geom_bar(stat = "identity")。

R：带有持续时间的ggplot

1 个答案: