将刻度和标签居中放置在条形GGplot的中间

library(ggplot2)

# 创建示例数据集
data <- data.frame(category = c("A", "B", "C", "D"),
                   value = c(10, 20, 15, 25))

# 创建条形图
plot <- ggplot(data, aes(x = category, y = value)) +
  geom_bar(stat = "identity", fill = "blue") +
  theme_minimal()

# 添加刻度和标签，并居中放置
plot <- plot + geom_text(aes(label = value), vjust = -0.5, hjust = 0.5)

# 显示图形
print(plot)