如何在ggplot自定义太阳burst图的geom_rect中手动设置矩形颜色

我想在ggplot的修改版太阳burst图中，为geom_rect的每个矩形手动设置特定颜色。目前只能用颜色渐变，但这个渐变在不同样本数据集之间无法匹配。

当前代码：

ggplot() + 
  scale_x_continuous(name="x") + 
  scale_y_continuous(name="y") +
  geom_rect(data=stroma_comp, mapping=aes(xmin=lower_lim, xmax=upper_lim,
                                          ymin=ymin,ymax=ymax, fill = stroma_gradient), color='black', alpha=0.5) +
  geom_col(data = plot_sample, mapping = aes(x = row_id, y = cd8_density_total)) +
  annotate("text", x = 1, y = -.004, label = sample_name, size = 7,
           color = "black") +
  geom_textpath(data = stroma_comp, 
            mapping = aes(x=lower_lim + (upper_lim-lower_lim)/2, y = ymin/2, 
                          label = stroma_bins), angle = 90, size = 2, color = "white") +
  theme_void() +
  scale_fill_discrete(guide = "none") +
  scale_color_discrete(guide = "none") +
  coord_polar()

当前输出效果：基于渐变配色的太阳burst图，颜色随stroma_gradient变量变化，但不同样本间配色无法统一。

期望的配色方案：

首次尝试匹配颜色的代码：

ggplot() + 
  scale_x_continuous(name="x") + 
  scale_y_continuous(name="y") +
  geom_rect(data=stroma_comp, mapping=aes(xmin=lower_lim, xmax=upper_lim,
                                          ymin=ymin,ymax=ymax), color='black', alpha=0.5) +
  scale_fill_manual(values = c("0-10% Stroma" = "00ffff",
                                 "10-20% Stroma" = "2efce7",
                                 "20-30% Stroma" = "50f8cd",
                                 "30-40% Stroma" = "6df3b3",
                                 "40-50% Stroma" = "87ed99",
                                 "50-60% Stroma" = "9fe681",
                                 "60-70% Stroma" = "b6de6b",
                                 "70-80% Stroma" = "cbd559",
                                 "80-90% Stroma" = "e0ca4d",
                                 "90-100% Stroma" = "f3be47")) +
  geom_col(data = plot_sample, mapping = aes(x = row_id, y = cd8_density_total)) +
  annotate("text", x = 1, y = -.004, label = sample_name, size = 7,
           color = "black") +
  geom_textpath(data = stroma_comp, 
            mapping = aes(x=lower_lim + (upper_lim-lower_lim)/2, y = ymin/2, 
                          label = stroma_bins), angle = 90, size = 2, color = "white") +
  theme_void() +
  scale_fill_discrete(guide = "none") +
  scale_color_discrete(guide = "none") +
  coord_polar()

该代码输出效果：未正确应用指定颜色，矩形呈现ggplot默认的离散配色，没有匹配期望的颜色方案。

补充数据（stroma_comp数据框）：

structure(list(stroma_bins = structure(1:10, levels = c("0-10% Stroma", 
"10-20% Stroma", "20-30% Stroma", "30-40% Stroma", "40-50% Stroma", 
"50-60% Stroma", "60-70% Stroma", "70-80% Stroma", "80-90% Stroma", 
"90-100% Stroma"), class = "factor"), n = c(12L, 4L, 19L, 72L, 
179L, 300L, 281L, 319L, 307L, 353L), upper_lim = c(12L, 16L, 
35L, 107L, 286L, 586L, 867L, 1186L, 1493L, 1846L), lower_lim = c(0L, 
12L, 16L, 35L, 107L, 286L, 586L, 867L, 1186L, 1493L), ymax = c(0, 
0, 0, 0, 0, 0, 0, 0, 0, 0), ymin = c(-0.002, -0.002, -0.002, 
-0.002, -0.002, -0.002, -0.002, -0.002, -0.002, -0.002)), class = "data.frame", row.names = c(NA, 
-10L))

你的代码存在三个关键问题导致配色失败：

1. 未绑定填充变量：geom_rect的aes中没有指定fill = stroma_bins，ggplot无法将手动设置的颜色与分箱变量关联。
2. 重复比例尺覆盖：先设置了scale_fill_manual，后续又用scale_fill_discrete(guide = "none")覆盖了手动配色，导致自定义颜色失效。
3. 颜色格式错误：十六进制颜色值缺少前缀#，ggplot无法正确识别这些颜色代码。

修正后的代码如下：

ggplot() + 
  scale_x_continuous(name="x") + 
  scale_y_continuous(name="y") +
  # 绑定fill到stroma_bins变量，建立颜色映射关系
  geom_rect(data=stroma_comp, mapping=aes(xmin=lower_lim, xmax=upper_lim,
                                          ymin=ymin,ymax=ymax, fill = stroma_bins), color='black', alpha=0.5) +
  # 添加#前缀修正颜色格式，同时在这里设置隐藏图例
  scale_fill_manual(values = c("0-10% Stroma" = "#00ffff",
                               "10-20% Stroma" = "#2efce7",
                               "20-30% Stroma" = "#50f8cd",
                               "30-40% Stroma" = "#6df3b3",
                               "40-50% Stroma" = "#87ed99",
                               "50-60% Stroma" = "#9fe681",
                               "60-70% Stroma" = "#b6de6b",
                               "70-80% Stroma" = "#cbd559",
                               "80-90% Stroma" = "#e0ca4d",
                               "90-100% Stroma" = "#f3be47"),
                    guide = "none") +
  geom_col(data = plot_sample, mapping = aes(x = row_id, y = cd8_density_total)) +
  annotate("text", x = 1, y = -.004, label = sample_name, size = 7,
           color = "black") +
  geom_textpath(data = stroma_comp, 
                mapping = aes(x=lower_lim + (upper_lim-lower_lim)/2, y = ymin/2, 
                              label = stroma_bins), angle = 90, size = 2, color = "white") +
  theme_void() +
  scale_color_discrete(guide = "none") +
  coord_polar()

修改后，每个stroma_bins对应的矩形会严格匹配你指定的固定颜色，且不同样本间的配色映射保持一致。

内容的提问来源于stack exchange，提问作者fgootkind