R报错'relevel' only for (unordered) factors

Error in relevel.default(diamonds_color_redefine$color, ref = "Common") : 
  'relevel' only for (unordered) factors

# 将有序的因子变量重新定义为无序的因子变量
diamonds_color_redefine$color <- factor(diamonds_color_redefine$color,
                                        levels = levels(diamonds_color_redefine$color),
                                        ordered = FALSE)

# 使用 relevel() 函数将约定的“Common”颜色设置为参考水平
diamonds_color_redefine$color <- relevel(diamonds_color_redefine$color, ref = "Common")