在 ggplot2 中填充热图（24 小时乘 7 天）

Question

我有这样的自行车数据 - 数据框的尺寸很大。

> dim(All_2014)
[1] 994367     10
> head(All_2014)
  X bikeid end.station.id start.station.id diff.time            stoptime           starttime
1 1  16379            285              356    338387 2014-01-02 15:22:28 2014-01-06 13:22:15
2 2  16379            361              146     47631 2014-01-09 22:45:34 2014-01-10 11:59:25
3 3  16379            268              327      5089 2014-01-10 12:35:22 2014-01-10 14:00:11
4 4  16379            398              324    715924 2014-01-22 14:34:55 2014-01-30 21:26:59
5 5  15611            536              445    716031 2014-01-02 15:30:44 2014-01-10 22:24:35
6 6  15611            348              433     68544 2014-01-12 14:03:01 2014-01-13 09:05:25
              midtime Hour      Day
1 2014-01-04 14:22:21   14 Saturday
2 2014-01-10 05:22:29    5   Friday
3 2014-01-10 13:17:46   13   Friday
4 2014-01-26 18:00:57   18   Sunday
5 2014-01-06 18:57:39   18   Monday
6 2014-01-12 23:34:13   23   Sunday

我的目标是使用 ggplot2（或其他包，如果它更适合）创建一个看起来像这个的热图，其中星期几在 y 轴上，小时在x 轴（小时不必在 AM/PM 中，它可以保持 24 小时制。：

方框的填充百分比表示在一周中的那一天给定的 hour-interval/the 总乘车次数中的乘车次数。我已经设法用数据做到了这一点，但想知道找到百分比的最简单方法，然后是如何用它们创建热图。

Answer 1

用dplyr做计算，用ggplot2做图表：

library(dplyr)
library(ggplot2)


## First siimulate some data
rider_num <- 1:10000
days <- factor(c("Sun", "Mon", "Tues", "Wed", "Thur", "Fri", "Sat"), 
               levels = rev(c("Sun", "Mon", "Tues", "Wed", "Thur", "Fri", "Sat")), 
               ordered = TRUE)

day <- sample(days, 10000, TRUE, 
              c(0.3, 0.5, 0.8, 0.8, 0.6, 0.5, 0.2))
hour <- round(rbeta(10000, 1, 2, 6) * 23)
df <- data.frame(rider_num, hour, day)

## Use dplyr functions to summarize on days and hours to get the 
## percentage of riders per hour each day:
df2 <- df %>% 
  group_by(day, hour) %>% 
  summarise(n=n()) %>% 
  mutate(percent_of_riders=n/sum(n)*100)

## Plot using ggplot and geom_tile, tweaking colours and theme elements
## to your liking:
ggplot(df2, aes(hour, day)) + 
  geom_tile(aes(fill = percent_of_riders), colour = "white") + 
  scale_fill_distiller(palette = "YlGnBu", direction = 1) +
  scale_x_discrete(breaks = 0:23, labels = 0:23) + 
  theme_minimal() +
  theme(legend.position = "bottom", legend.key.width = unit(2, "cm"),
        panel.grid = element_blank()) + 
  coord_equal()

Answer 2

使用@andyteucher 的 df2，这是一个 lattice 方法：

library(lattice)
library(RColorBrewer)
levelplot(percent_of_riders~hour+day, df2, 
          aspect='iso', xlab='', ylab='', border='white',
          col.regions=colorRampPalette(brewer.pal(9, 'YlGnBu')),
          at=seq(0, 12, length=100), # specify breaks for the colour ramp
          scales=list(alternating=FALSE, tck=1:0, x=list(at=0:23)))

用零替换缺失数据（例如周日午夜）的一种简单方法是将 xtabs 对象传递给 levelplot：

levelplot(xtabs(percent_of_riders ~ hour+day, df2), aspect='iso', xlab='', ylab='',
          col.regions=colorRampPalette(brewer.pal(9, 'YlGnBu')),
          at=seq(0, 12, length=100),
          scales=list(alternating=FALSE, tck=1:0),
          border='white')

您还可以使用 d3heatmap 进行互动：

library(d3heatmap)
xt <- xtabs(percent_of_riders~day+hour, df2)
d3heatmap(xt[7:1, ], colors='YlGnBu', dendrogram = "none")

在 ggplot2 中填充热图（24 小时乘 7 天）

fill a heat map (24h by 7days) in ggplot2

r

heatmap

ggplot2