geom_text - 使按颜色分组的绘图的文本变黑

Posted 2023-02-16

【中文标题】geom_text - 使按颜色分组的绘图的文本变黑

【英文标题】：geom_text - make text black for plot grouped by color

【发布时间】：2021-11-25 13:11:12

【问题描述】：

我有一个按颜色分组的图表，每个点上方的文本中都有值。但是，我想要黑色的文字，因为它很难阅读。

我能否在不丢失定位的情况下将文本颜色从 geom_text() 更改为黑色？

将color = "black" 添加到 geom_text() 会弄乱文本的位置，但我不知道为什么...

我的数据：

structure(list(type = c("full", "full", "full", "noadiposity", 
"noadiposity", "noadiposity", "nocv", "nocv", "nocv", "nocv2", 
"nocv2", "nocv2", "noenergy", "noenergy", "noenergy", "noenergy2", 
"noenergy2", "noenergy2"), fi.cat = structure(c(1L, 2L, 3L, 1L, 
2L, 3L, 1L, 2L, 3L, 1L, 2L, 3L, 1L, 2L, 3L, 1L, 2L, 3L), .Label = c("Non-frail", 
"Pre-frail", "Frail"), class = "factor"), mean = c(0.0566154812663495, 
0.150817937965167, 0.285714285714286, 0.0459153181095795, 0.148380746409361, 
0.292192760942761, 0.0550705669171458, 0.147270820014587, 0.288461538461538, 
0.0530093023576546, 0.145279762712841, 0.292717236467236, 0.0531040684693624, 
0.146793227463497, 0.292499719195777, 0.054311319499867, 0.14824350913368, 
0.283745781777278), sd = c(0.0289882935363143, 0.0342654979144937, 
0.0393662413936823, 0.0298601819635622, 0.0345078387756546, 0.0422635938212309, 
0.0285280200524055, 0.0338893364029561, 0.0430877768970245, 0.0275365612798787, 
0.0358119253511248, 0.0415426999110631, 0.0270394224053038, 0.0374836297491701, 
0.0384867847822804, 0.0280882098015465, 0.0353023978795509, 0.039235018559239
)), row.names = c(NA, -18L), groups = structure(list(type = c("full", 
"noadiposity", "nocv", "nocv2", "noenergy", "noenergy2"), .rows = structure(list(
    1:3, 4:6, 7:9, 10:12, 13:15, 16:18), ptype = integer(0), class = c("vctrs_list_of", 
"vctrs_vctr", "list"))), row.names = c(NA, -6L), class = c("tbl_df", 
"tbl", "data.frame"), .drop = TRUE), class = c("grouped_df", 
"tbl_df", "tbl", "data.frame"))

我使用的代码：

library(ggplot2)

ggplot(grouped_mean, aes(x = fi.cat, y = mean, color = type)) +
  geom_point(position = position_dodge(0.9), size = 2) + 
  geom_errorbar(aes(ymin = mean-sd, ymax = mean+sd), position = position_dodge(0.9), size = 1, width = 0.2) +
  geom_text(aes(label = round(mean, 2)), vjust = -5.5, position = position_dodge(0.9), size = 3) +
  labs(x = "FI category", y = "Mean FI score", color = "FI type") +
  scale_color_brewer(palette = "Blues") +
  theme_minimal()

【参考方案1】：

使用点和误差线的颜色会自动将它们分成组。如果您手动分配颜色，则需要在 geom_text() 中指定组，即：

ggplot(grouped_mean, aes(x = fi.cat, y = mean, color = type)) +
  geom_point(position = position_dodge(0.9), size = 2) + 
  geom_errorbar(aes(ymin = mean-sd, ymax = mean+sd), position = position_dodge(0.9), size = 1, width = 0.2) +
  # Add grouping and manual colour to geom_text
  geom_text(aes(label = round(mean, 2), group=type), colour="black", vjust = -5.5, position = position_dodge(0.9), size = 3) +
  labs(x = "FI category", y = "Mean FI score", color = "FI type") +
  scale_color_brewer(palette = "Blues") +
  theme_minimal()

【参考方案2】：

这是一种方法：不是最好的方法，但它似乎有效！ 此方法使用fill 美学并将颜色美学单独分配给geom_text 美学：

library(ggplot2)

ggplot(grouped_mean, aes(x = fi.cat, y = mean, fill=type)) +
  geom_point(position = position_dodge(0.9), size = 2) + 
  geom_errorbar(aes(ymin = mean-sd, ymax = mean+sd), position = position_dodge(0.9), size = 1, width = 0.2) +
  geom_text(aes(label = round(mean, 2)), vjust =-11.5, position = position_dodge(0.9), size = 3) +
  labs(x = "FI category", y = "Mean FI score", color = "FI type") +
  geom_point(aes(color=type), position = position_dodge(0.9), size = 2) + 
  geom_errorbar(aes(color=type, ymin = mean-sd, ymax = mean+sd), position = position_dodge(0.9), size = 1, width = 0.2) +
  scale_color_brewer(palette = "Blues") +
  theme_minimal()+
  guides(fill = "none")

【讨论】：

谢谢，但由于解释的原因，我接受了上述作为答案，而且行数更少。

MIff 答案绝对是更好更正确的答案！:-)