r - 拉伸(stretch) x 轴并将不同的 binwidth 应用于 ggplot2 R 中直方图中的值范围

Question

这是我想要构建的示例 ggplot。在我的数据中，我有一个问题，即我在直方图的小范围内有很多值。因此，我想让 x 轴不成比例地拉伸(stretch)(此处介于 80,81,82,83,84,85 的值之间)。因此，刻度线将在图表上均匀分布，并且刻度线之间的空间不会与该图表上值的增量增加成比例。因此，我还想对直方图的那部分应用不同的 bin 大小(假设 binwidth = 1)。

library(ggplot2)

set.seed(42)
data <- data.frame(c(rnorm(mean=80,sd=20,30)),seq(1,30,1),
                   c("A","B","B","A","A","B","B","A","A","A",
                     "A","B","B","A","A","B","B","A","A","B",
                     "B","A","A","B","B","A","A","B","B","A"))
colnames(data) <- c("vals","respondent","category")
# Plot the number of vals
ggplot(data,aes(x = vals,fill = category)) + 
        geom_histogram(position = "stack",binwidth = 5) +
        ggtitle("plot")+
        #scale_x_continuous(c(40,50,60,70,80,81,82,83,84,85,95,105,115))+
        theme_minimal() +
        ylab("Number of respondents")+xlab("Number of vals")

Answer 1

您可以自己计算尺寸(宽度/高度)，作为一系列堆叠的矩形。

使用钻石数据集进行说明，假设这是我们的原始直方图，我们想要放大 [500, 1000] 价格范围:

ggplot(diamonds,
       aes(x = price, fill = color)) +
  geom_histogram(binwidth = 500) +
  theme_bw()

定义您喜欢的轴中断:

x.axis.breaks <- c(0,                      # binwidth = 500
                   seq(500, 900, 100),     # binwidth = 100
                   seq(1000, 19000, 500))  # binwidth = 500
> x.axis.breaks
 [1]     0   500   600   700   800   900  1000  1500  2000  2500  3000  3500  4000  4500
[15]  5000  5500  6000  6500  7000  7500  8000  8500  9000  9500 10000 10500 11000 11500
[29] 12000 12500 13000 13500 14000 14500 15000 15500 16000 16500 17000 17500 18000 18500
[43] 19000

计算每个区间的 xmin/xmax/ymin/ymax:

library(dplyr)

diamonds2 <- diamonds %>%
  mutate(price.cut = cut(price,
                         breaks = x.axis.breaks)) %>%
  count(price.cut, color) %>%
  mutate(xmin = x.axis.breaks[as.integer(price.cut)],
         xmax = x.axis.breaks[as.integer(price.cut) + 1]) %>%
  group_by(price.cut) %>%
  arrange(desc(color)) %>%
  mutate(ymax = cumsum(n)) %>%
  mutate(ymin = lag(ymax)) %>%
  mutate(ymin = ifelse(is.na(ymin), 0, ymin)) %>%
  ungroup()

> diamonds2
# A tibble: 294 x 7
   price.cut color     n  xmin  xmax  ymax  ymin
   <fct>     <ord> <int> <dbl> <dbl> <int> <dbl>
 1 0         J       158     0   500   158     0
 2 500       J        80   500   600    80     0
 3 600       J        84   600   700    84     0
 4 700       J        51   700   800    51     0
 5 800       J        43   800   900    43     0
 6 900       J        47   900  1000    47     0
 7 1000      J       145  1000  1500   145     0
 8 1500      J       198  1500  2000   198     0
 9 2000      J       163  2000  2500   163     0
10 2500      J        72  2500  3000    72     0
# ... with 284 more rows

剧情:

p <- ggplot(diamonds2,
       aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymax, fill = color)) +
  geom_rect() +
  theme_bw()

p

我不倾向于“拉伸(stretch)”连续轴的一部分，因为它会扭曲解释。但是您可以使用 ggforce 包中的 facet_zoom 进行放大:

library(ggforce)

p + facet_zoom(x = xmin >= 500 & xmax <= 1000)

如果您不希望相邻条在缩放面中可见，请将 x 轴范围扩展参数设置为 0。

p + 
  facet_zoom(x = xmin >= 500 & xmax <= 1000) +
  scale_x_continuous(expand = c(0, 0))

编辑

要在自定义标签的末尾有不同的 binwidth，您可以进行以下更改:

# use even binwidth (500) up to 15000, then jump to the end
x.axis.breaks <- c(0,                      # binwidth = 500
                   seq(500, 900, 100),     # binwidth = 100
                   seq(1000, 15000, 500),  # binwidth = 500
                   19000)                  # everything else

# reduce the largest xmax value in order to have the same bar width
diamonds2 <- diamonds2 %>%
  mutate(xmax = ifelse(xmax == max(xmax),
                       xmin + 500,
                       xmax))

# define breaks & labels for x-axis
p <- p +
  scale_x_continuous(breaks = seq(0, 15000, 5000),
                     labels = c(seq(0, 10000, 5000),
                                "15000+"))