Stacked column chart绘制求助：柱内值顺序颠倒+自定义颜色失效

问题1：柱内数值顺序颠倒 #

你的代码里，data_long$A <- factor(data_long$A, levels = rev(levels(data_long$A)))这行写在了数据重塑之前，此时data_long还未生成，所以这行代码完全没有生效。

两种修复方式： #

方式1：先重塑数据再调整因子水平

col_names <- c("A", "B", "C", "D","E", "F", "G","H")  
colnames(data) <- col_names

# 先完成数据重塑
data_long <- tidyr::pivot_longer(data, cols = c(B:H), names_to = "X", values_to = "Value")
# 再调整A的因子水平，反转默认顺序以匹配Excel效果
data_long$A <- factor(data_long$A, levels = rev(levels(data_long$A)))

ggplot(data_long, aes(x = X, y = Value, fill = A)) +
  geom_col(position = "stack") +
  labs(x = "X轴", y = "Y轴", fill = "图例") +
  theme_minimal()

方式2：直接反转堆叠顺序

如果不想修改因子水平，可在geom_col中设置堆叠参数：

ggplot(data_long, aes(x = X, y = Value, fill = A)) +
  geom_col(position = position_stack(reverse = TRUE)) + # 反转堆叠顺序
  labs(x = "X轴", y = "Y轴", fill = "图例") +
  theme_minimal()

问题2：自定义HEX颜色显示灰色 #

出现灰色通常是因为自定义颜色的数量和因子A的类别数量不匹配，或者颜色向量未与因子水平对应。

修复代码： #

确保自定义颜色的数量与A列的类别数一致，用scale_fill_manual指定：

# 示例：根据A列实际类别数调整颜色数量
custom_colors <- c("#FF5733", "#33FF57", "#3357FF", "#FF33A6")

ggplot(data_long, aes(x = X, y = Value, fill = A)) +
  geom_col(position = position_stack(reverse = TRUE)) +
  scale_fill_manual(values = custom_colors) + # 指定自定义HEX颜色
  labs(x = "X轴", y = "Y轴", fill = "图例") +
  theme_minimal()

如果要严格绑定颜色与特定类别，可给颜色向量命名：

custom_colors <- c(
  "类别1" = "#FF5733",
  "类别2" = "#33FF57",
  "类别3" = "#3357FF",
  "类别4" = "#FF33A6"
)

完整修复代码 #

col_names <- c("A", "B", "C", "D","E", "F", "G","H")  
colnames(data) <- col_names

# 数据重塑
data_long <- tidyr::pivot_longer(data, cols = c(B:H), names_to = "X", values_to = "Value")

# 自定义颜色（根据A列实际类别数量调整）
custom_colors <- c("#FF5733", "#33FF57", "#3357FF", "#FF33A6", "#F3FF33")

ggplot(data_long, aes(x = X, y = Value, fill = A)) +
  geom_col(position = position_stack(reverse = TRUE)) + # 修正堆叠顺序
  scale_fill_manual(values = custom_colors) + # 自定义颜色
  labs(x = "X轴", y = "Y轴", fill = "图例") +
  theme_minimal()

内容的提问来源于stack exchange，提问作者Erika Eri