r - 你如何为ggplot中的条形图在x轴上做范围？

Question

我正在创建一个条形图，并且需要能够在 x 轴上有范围。

示例数据

Redear Sunfish  195

Redear Sunfish  210

Redear Sunfish  212

Redear Sunfish  215

Redear Sunfish  235

Redear Sunfish  242

我想了解这些鱼的大小（例如 50 - 100 毫米、100 - 150 毫米等）。

我现在的代码是

ggplot(data=Sunfish_Total_Length)+
  geom_bar(mapping=aes(x=Total_Length_mm))

谢谢您的帮助！

标签： rggplot2graphrange

Answer 1

如果我正确理解了这个问题，一个潜在的解决方案是使用该cut()功能，例如

library(tidyverse)

Sunfish_Total_Length <- tribble(
  ~"Species", ~"Total_Length_mm",
  "Redear Sunfish", 195,
  "Redear Sunfish",  210,
  "Redear Sunfish",  212,
  "Redear Sunfish",  215,
  "Redear Sunfish",  235,
  "Redear Sunfish",  242
  )

Sunfish_Total_Length %>% 
  mutate(`Size Category (mm)` = cut(Total_Length_mm, breaks = seq(0, 250, 50))) %>%
  ggplot(data = ., aes(x = `Size Category (mm)`)) +
  geom_bar()

^{由reprex 包于 2021-08-17 创建 (v2.0.0 )}

--

'Non-tidyverse' 样式代码：

# Non-pipe notation (i.e. no "%>%")
library(ggplot2)

Sunfish_Total_Length <- data.frame(
  stringsAsFactors = FALSE,
  Species = c(
    "Redear Sunfish",
    "Redear Sunfish",
    "Redear Sunfish",
    "Redear Sunfish",
    "Redear Sunfish",
    "Redear Sunfish"
  ),
  Total_Length_mm = c(195, 210, 212, 215, 235, 242)
)
Sunfish_Total_Length
#>          Species Total_Length_mm
#> 1 Redear Sunfish             195
#> 2 Redear Sunfish             210
#> 3 Redear Sunfish             212
#> 4 Redear Sunfish             215
#> 5 Redear Sunfish             235
#> 6 Redear Sunfish             242

Sunfish_Total_Length$`Size Category (mm)` <- cut(Sunfish_Total_Length$Total_Length_mm, breaks = seq(0, 250, 50))
Sunfish_Total_Length
#>          Species Total_Length_mm Size Category (mm)
#> 1 Redear Sunfish             195          (150,200]
#> 2 Redear Sunfish             210          (200,250]
#> 3 Redear Sunfish             212          (200,250]
#> 4 Redear Sunfish             215          (200,250]
#> 5 Redear Sunfish             235          (200,250]
#> 6 Redear Sunfish             242          (200,250]

ggplot(data = Sunfish_Total_Length, aes(x = `Size Category (mm)`)) +
  geom_bar()

^{由reprex 包于 2021-08-17 创建 (v2.0.0 )}