求助：移除ggplot2金字塔图X轴负值及解决number_format函数报错

1. 搞定"number_format函数未找到"的报错 #

number_format() 是scales包里的函数，必须先加载scales包才能调用：

library(scales)

2. 移除X轴负值显示的两种实用方法 #

方法一：自定义标签函数（简单直接，无额外配置） #

在scale_x_continuous()里用匿名函数把坐标轴上的负数转成正数，同时保留金字塔的左右结构：

ggplot(your_data, aes(x = value, y = age_group, fill = gender)) +
  geom_col(position = "identity") +
  scale_x_continuous(labels = ~abs(.x), expand = c(0, 0)) # 核心：用abs()转换为绝对值
  labs(x = "人口数", y = "年龄组", fill = "性别") +
  theme_classic()

方法二：用scales::number_format做格式化（适合需千分位等场景） #

如果要给数值添加千分位或其他格式，可通过number_format()的transform参数传入abs函数：

ggplot(your_data, aes(x = value, y = age_group, fill = gender)) +
  geom_col(position = "identity") +
  scale_x_continuous(
    labels = number_format(transform = abs, big.mark = ","), # 转绝对值+千分位分隔
    expand = c(0, 0)
  ) +
  labs(x = "人口数", y = "年龄组", fill = "性别") +
  theme_classic()

可选：从数据层面优化 #

要是不想让原始数据中出现负值，可先预处理把所有数值转成正数，再给男性组映射负号到X轴，最后同样用绝对值显示标签：

your_data <- your_data %>% mutate(pop = abs(value))

ggplot(your_data, aes(x = ifelse(gender == "Male", -pop, pop), y = age_group, fill = gender)) +
  geom_col(position = "identity") +
  scale_x_continuous(labels = abs, expand = c(0, 0)) +
  labs(x = "人口数", y = "年龄组", fill = "性别")

内容的提问来源于stack exchange，提问作者Eddie