如何使用 ggplot2 绘制矩阵并为相同的值保持相同的颜色

Question

我正在使用 ggplot2 绘制存储在 12 个矩阵中的值。每个矩阵单元格可以包含一个从 1 到 10 的数字，我使用 ggplot2 来绘制这些值：

col<-c("red", "orange", "blue", "cyan", "green", "lightgreen", "violet", "pink", "black", "brown")
tdm <- melt(node10den0.7)
ggplot(tdm, aes(x = Var2, y = Var1, fill = factor(value))) +
labs(x = "Cost", y = "Benefit", fill = "Value", title="10 nodes, den=0.7") +
geom_raster() +
scale_fill_manual("Legend", breaks = c("1","2","3","4","5","6","7","8","9","10"),
                  values = col, labels=c("null", "n-null", "star", "n-star", "bistar", "n-bistar", "shared", "n-shared", "complete", "n-complete")) +
theme(plot.background = element_rect(fill = "grey90"),
      legend.background = element_rect(fill = "grey90")) +
scale_x_continuous(expand = c(0, 0)) +
scale_y_continuous(expand = c(0, 0))

我的问题是并非所有矩阵都包含所有可能的值，所以我看到某些图中某些值的颜色发生了变化......有没有办法保持颜色固定？如果你在矩阵中看到 2 然后将其绘制为红色？

第二个问题：是否可以让ggplot2在图例中显示所有可能的颜色/标签？

我添加了几个矩阵作为示例：

> dput(node3den0)
structure(c(2, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 
8, 2, 0, 2, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 2, 2, 
0, 0, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 2, 2, 2, 0, 0, 
0, 2, 2, 8, 8, 8, 8, 8, 8, 8, 8, 8, 2, 2, 2, 2, 2, 0, 0, 0, 0, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 10, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 
2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 2, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 2, 2, 2, 2, 2, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 2), .Dim = c(19L, 19L), .Dimnames = list(
c("0.05", "0.1", "0.15", "0.2", "0.25", "0.3", "0.35", "0.4", 
"0.45", "0.5", "0.55", "0.6", "0.65", "0.7", "0.75", "0.8", 
"0.85", "0.9", "0.95"), c("0.05", "0.1", "0.15", "0.2", "0.25", 
"0.3", "0.35", "0.4", "0.45", "0.5", "0.55", "0.6", "0.65", 
"0.7", "0.75", "0.8", "0.85", "0.9", "0.95")))

> dput(node10den0.7)
structure(c(3, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 
8, 7, 0, 3, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 2, 
0, 0, 10, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 7, 2, 0, 
0, 2, 3, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 7, 7, 2, 2, 0, 0, 0, 
10, 3, 7, 7, 2, 7, 7, 7, 7, 7, 7, 7, 7, 2, 2, 2, 0, 0, 0, 10, 
10, 3, 7, 7, 7, 7, 7, 7, 7, 7, 7, 2, 2, 2, 2, 0, 0, 0, 0, 2, 
2, 3, 2, 7, 7, 7, 7, 7, 7, 2, 2, 2, 2, 3, 0, 0, 0, 0, 2, 3, 3, 
3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 0, 0, 0, 0, 2, 2, 10, 10, 
3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 10, 0, 0, 0, 0, 0, 10, 10, 3, 3, 
3, 2, 2, 2, 2, 2, 2, 2, 2, 10, 0, 0, 0, 0, 0, 2, 2, 2, 3, 3, 
3, 2, 2, 2, 2, 2, 2, 2, 7, 0, 0, 0, 0, 0, 3, 3, 10, 10, 2, 3, 
3, 2, 2, 2, 2, 2, 7, 7, 0, 0, 0, 0, 0, 3, 10, 3, 2, 10, 3, 2, 
3, 2, 2, 2, 2, 3, 7, 0, 0, 0, 0, 0, 0, 2, 3, 2, 2, 3, 2, 3, 3, 
2, 2, 2, 3, 7, 0, 0, 0, 0, 0, 0, 2, 2, 3, 3, 2, 3, 3, 2, 3, 2, 
2, 10, 7, 0, 0, 0, 0, 0, 0, 2, 10, 3, 3, 2, 3, 10, 2, 3, 10, 
3, 7, 7, 0, 0, 0, 0, 0, 0, 0, 3, 3, 2, 3, 3, 10, 2, 3, 3, 3, 
10, 7, 0, 0, 0, 0, 0, 0, 0, 3, 10, 10, 2, 10, 3, 3, 2, 2, 3, 
3, 10, 0, 0, 0, 0, 0, 0, 0, 10, 2, 3, 3, 3, 2, 3, 2, 2, 10, 2, 
7), .Dim = c(19L, 19L), .Dimnames = list(c("0.05", "0.1", "0.15", 
"0.2", "0.25", "0.3", "0.35", "0.4", "0.45", "0.5", "0.55", "0.6", 
"0.65", "0.7", "0.75", "0.8", "0.85", "0.9", "0.95"), c("0.05", 
"0.1", "0.15", "0.2", "0.25", "0.3", "0.35", "0.4", "0.45", "0.5", 
"0.55", "0.6", "0.65", "0.7", "0.75", "0.8", "0.85", "0.9", "0.95"
)))

最好的问候， 西蒙娜

Answer 1

使用limits 参数。使用您的第一个矩阵：

col<-c("red", "orange", "blue", "cyan", 
       "green", "lightgreen", "violet", "pink", "black", "brown", "yellow")
ggplot(tdm, aes(x = Var2, y = Var1, fill = factor(value))) +
  labs(x = "Cost", y = "Benefit", fill = "Value", title="10 nodes, den=0.7") +
  geom_raster() +
  scale_fill_manual("Legend", limits = 0:10,
                    values = col, 
                    labels=c("null", "n-null", "star", "n-star", "bistar", 
                      "n-bistar", "shared", "n-shared", "complete", "n-complete",
                      "additional")) +
  theme(plot.background = element_rect(fill = "grey90"),
        legend.background = element_rect(fill = "grey90")) +
  scale_x_continuous(expand = c(0, 0)) +
  scale_y_continuous(expand = c(0, 0))

请注意，我添加了一个颜色值，因为您的可能值似乎从 0 到 10。