如何处理 R ggplot 中的长图例标签

Question

我正在对股票指数进行部门比较，我想显示员工人数与利润、销售额等的相关性。但是，当我尝试将 plot 与 colors 进行不同部门的散布并添加图例时，因为该部门名称是这么久，plot 变得不可读了。 我可以让它与分面一起工作，但我想在一个 plot 中显示所有部门数据，以便于比较。

这是玩具数据框

structure(list(Dates = c("2021-12-31", "2021-12-31", "2021-12-31", 
"2021-12-31", "2021-12-31", "2021-12-31", "2021-12-31", "2021-12-31", 
"2021-12-31", "2021-12-31", "2021-12-31", "2021-12-31", "2021-12-31", 
"2021-12-31", "2021-12-31"), Firm = c("BRYAT", "ZRGYO", "KONTR", 
"TRGYO", "DAPGM", "INVES", "ECZYT", "GWIND", "KMPUR", "SNGYO", 
"BERA", "ISGYO", "ALKA", "YGGYO", "SRVGY"), Sector = c("FINANCIAL AND INSURANCE ACTIVITIES", 
"FINANCIAL AND INSURANCE ACTIVITIES", "INFORMATION AND COMMUNICATION", 
"REAL ESTATE ACTIVITIES", "REAL ESTATE ACTIVITIES", "FINANCIAL AND INSURANCE ACTIVITIES", 
"FINANCIAL AND INSURANCE ACTIVITIES", "MANUFACTURING", "MANUFACTURING", 
"REAL ESTATE ACTIVITIES", "MANUFACTURING", "REAL ESTATE ACTIVITIES", 
"MANUFACTURING", "FINANCIAL AND INSURANCE ACTIVITIES", "FINANCIAL AND INSURANCE ACTIVITIES"
), `Number of Employees` = c(9, 32, 226, 144, 138, 6, 3, 50, 
219, 194, 33, 69, 208, 138, 11), EBITDA = c(23.8137, 1113.5212, 
113.9684, 6517.373, 387.6152, 1624.0192, -7.8884, 420.6019, 280.8024, 
4648.4098, 752.1899, 153.6431, 138.7504, 194.0958, 144.2635), 
    `Profit Margin` = c(574.7712, 706.7635, 21.3576, 357.6667, 
    34.2274, 537.1883, 372.8143, 31.6373, 14.5637, 150.702, 17.7025, 
    48.8762, 26.2978, 252.0494, 162.3127), Sales = c(47.7833, 
    186.8011, 611.8077, 1483.729, 912.4001, 312.5418, 0, 540.2263, 
    2172.6885, 2123.4395, 4217.1842, 545.2598, 700.9869, 277.6963, 
    414.2354), `Market Cap` = c(10681.875, 11405.4966, 2474.0625, 
    3920, NA, NA, 5407.5, 3123.1821, NA, 3728.536, 3320.352, 
    2435.225, 859.425, 3386.88, 4695.6), `Personnel Expense (Millions)` = c(3.4716, 
    8.4842, 7.7846, 11.869, 14.3014, 1.1789, 0.4507, 17.2696, 
    55.9705, 25.5093, 308.7577, 20.0843, 33.358, 10.5289, 14.3268
    ), `Personnel Expense Per Employee` = c(385733.5556, 265130.0938, 
    34445.1726, 82423.6111, 103633.6739, 196478.3333, 150236.6667, 
    345392.94, 255573.0411, 131491.1082, 9356294.7879, 291076.971, 
    160374.9663, 76296.7319, 1302436.6364), `Price/Earnings` = c(38.8935, 
    7.8922, 18.934, 0.7387, NA, NA, 12.5925, 18.2735, NA, 1.1651, 
    4.4476, 9.1377, 4.6621, 4.6933, 6.9838)), row.names = c(NA, 
-15L), class = c("tbl_df", "tbl", "data.frame"))

我试图使图例文本字体更小，但这次图例变得不可读。 我很确定我可以包装文本，但我真的找不到代码。

ggplot(dataset%>%
               filter(Dates %in% "2021-12-31" & `Number of Employees` < 250))+
        geom_point(aes(x = `Number of Employees`, y  = `Profit Margin`, color = Sector),show.legend = T)+
    lims(y = c(-100,200))+
    theme(legend.text = element_text(size = 6,hjust = 0.5,lineheight = 121))

Answer 1

我建议您将图例移到底部（或顶部）并设置行数：

dataset %>%
  filter(Dates %in% "2021-12-31", `Number of Employees` < 250) %>%
  ggplot(aes(x = `Number of Employees`, y = `Profit Margin`)) +
  geom_point(aes(color = Sector)) +
  lims(y = c(-100,200)) +
  theme(
    legend.text = element_text(size = 6,hjust = 0.5, lineheight = 121), 
    legend.position = "bottom") +
  guides(color = guide_legend(nrow = 2))

Answer 2

我查看了 Hadley Wickham 的 GitHub 并找到legend.key.size()和legend.key.width()选项。

dataset %>%
  filter(Dates %in% "2021-12-31", `Number of Employees` < 250) %>%
  ggplot(aes(x = `Number of Employees`, y = `Profit Margin`)) +
  geom_point(aes(color = Sector)) +
  lims(y = c(-50,200)) +
  theme(
    legend.text = element_text(size = 5,vjust = 0.1), 
    legend.position = "bottom",
    legend.key.width = unit(0.05, "cm"),
    legend.key.size = unit(0.1, "cm"))+
  guides(color = guide_legend(ncol  = 3, nrow = 5))

Answer 3

比例尺 package 提供label_wrap()以在指定字符数后的自然断点处换行长字符串。 结合 r2evans 关于图例定位和格式的建议，您应该能够为许多标签实现可读文本。

dataset %>%
  filter(Dates %in% "2021-12-31" & `Number of Employees` < 250) %>%
  ggplot(aes(x = `Number of Employees`, y = `Profit Margin`, color = Sector)) +
  geom_point(size = 3) +
  scale_colour_viridis_d(
    option = "turbo", end = 0.8,
    labels = scales::label_wrap(20),
    guide = guide_legend(nrow = 2)
  ) +
  theme_bw() +
  theme(
    legend.text = element_text(size = 7, hjust = 0.5), 
    legend.key.height = unit(10, "mm"), # increase this to space out the wrapped labels
    legend.position = "bottom" # might be more space down here, depends on plot dimensions
  )

14 种不同的颜色会很棘手，我的建议是使用/滥用涡轮调色板，如上所述，或者考虑使用形状和颜色来区分您的类别。