在ggplot2中填写热图(24小时7天)

Question

我有自行车数据,看起来像这样 - 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(或其他包装,如果它更适合)创建一个热图,看起来像这样,一周中的星期几在y轴上,小时在x轴上(小时没有在上午/下午,它可以保持24小时规模:

方框的填充是一个百分比,表示在给定的小时间隔内的骑行量/一周中当天的总骑行量.我已经设法使用这些数据,但想知道查找百分比的最简单方法,然后,如何使用它们创建热图.

Answer 1

使用dplyr进行计算,使用ggplot2进行计算:

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()