python - plotnine/ggplot - 改变图例位置

Question

我有这个数据框：

df = pd.DataFrame({'ymin': {0: 0.0,
  1: 0.0,
  2: 0.0,
  3: 0.0,
  4: 0.511,
  5: 0.571,
  6: 0.5329999999999999,
  7: 0.5389999999999999},
 'ymax': {0: 0.511,
  1: 0.571,
  2: 0.533,
  3: 0.539,
  4: 1.0,
  5: 1.0,
  6: 1.0,
  7: 1.0},
 'xmin': {0: 0.0,
  1: 0.14799999999999996,
  2: 0.22400000000000003,
  3: 0.5239999999999999,
  4: 0.0,
  5: 0.14799999999999996,
  6: 0.22400000000000003,
  7: 0.5239999999999999},
 'xmax': {0: 0.148,
  1: 0.22399999999999998,
  2: 0.524,
  3: 1.001,
  4: 0.148,
  5: 0.22399999999999998,
  6: 0.524,
  7: 1.001},
 'variable': {0: 'A', 1: 'A', 2: 'A', 3: 'A', 4: 'B', 5: 'B', 6: 'B', 7: 'B'}})

我在哪里绘制这个：

(ggplot(df, aes(ymin = "ymin", ymax = "ymax",
     xmin = "xmin", xmax = "xmax", fill = "variable"))
 + geom_rect(colour = "grey", alpha=0.7))

我希望将图例的位置更改为与情节的位置相同：蓝色向上和红色底部。永远A是红色的，B永远是蓝色的

标签： pythonggplot2plotnine

Answer 1

可能有一种更标准的方法来做到这一点，但这里有一个快速解决问题的方法：

1. 更改变量的顺序

2. 手动分配颜色（如果对您的情况很重要，您也可以查找确切的颜色代码并将其替换为颜色名称）

    df = df.assign(variable = pd.Categorical(df['variable'], ['B', 'A']))
   
    (ggplot(df, aes(ymin = "ymin", ymax = "ymax",
        xmin = "xmin", xmax = "xmax", fill = "variable"))+
        geom_rect(colour = "grey", alpha=0.7)+
        scale_fill_manual(values = ["blue", "red"]))
   

输出如下所示：