仅更改 ggplot2 中热图的上三角矩阵的颜色

Question

我有这个融化的矩阵，我想将其绘制为热图，下部矩阵具有相关系数，上部三角形具有 P 值

> melted_corfinal
     Var1   Var2 value
1     iHS    iHS  1.00
2     nSL    iHS  0.89
3  XP-EHH    iHS  0.01
4     PBS    iHS  0.00
5     iHS    nSL  0.00
6     nSL    nSL  1.00
7  XP-EHH    nSL  0.01
8     PBS    nSL  0.00
9     iHS XP-EHH  0.00
10    nSL XP-EHH  0.00
11 XP-EHH XP-EHH  1.00
12    PBS XP-EHH  0.18
13    iHS    PBS  0.90
14    nSL    PBS  0.41
15 XP-EHH    PBS  0.00
16    PBS    PBS  1.00

但是，我找不到一种方法来仅更改上三角矩阵的颜色，同时保持值不变。我希望它只是白色（背景）。

这里是我到目前为止提出的代码：

p <- ggplot(melted_corfinal, aes(Var2, Var1)) +
  geom_tile(aes(fill = value)) + 
  geom_text(aes(label = round(value, 2))) +
  scale_fill_continuous("",limits=c(0, 1), breaks=seq(0,1,by=0.2),low = "#fee8c8", high = "#e34a33") + 
  theme_light() + theme(legend.position="none",axis.title.x = element_blank(),axis.title.y = element_blank()) +
  guides(fill = guide_colorbar(barwidth = 20)) +
  ylim(rev(levels(melted_corfinal$Var1))) + xlim(levels(melted_corfinal$Var2))

plot(p)

此外，我仍然希望 table 中保留 2 个小数位，但当它们为零时它们是 "rounded"。输入：

structure(list(Var1 = structure(c(1L, 2L, 3L, 4L, 1L, 2L, 3L, 
4L, 1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L), .Label = c("iHS", "nSL", 
"XP-EHH", "PBS"), class = "factor"), Var2 = structure(c(1L, 1L, 
1L, 1L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L), .Label = c("iHS", 
"nSL", "XP-EHH", "PBS"), class = "factor"), value = c(1, 0.89, 
0.01, 0, 0, 1, 0.01, 0, 0, 0, 1, 0.18, 0.9, 0.41, 0, 1)), .Names = c("Var1", 
"Var2", "value"), row.names = c(NA, -16L), class = "data.frame")

Answer 1

好的，首先我将您提供的数据转换回常规未熔化矩阵，这样我就可以轻松地将上三角设置为 NA。我使用 dcast 执行此操作。该矩阵已经是对角线和下三角的相关性以及上三角的 p 值的组合。

melted_corfinal <- structure(list(Var1 = structure(c(1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L), 
                                                   .Label = c("iHS", "nSL", "XP-EHH", "PBS"), class = "factor"), 
                                  Var2 = structure(c(1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L), 
                                                   .Label = c("iHS", "nSL", "XP-EHH", "PBS"), class = "factor"), 
                                  value = c(1, 0.89, 0.01, 0, 0, 1, 0.01, 0, 0, 0, 1, 0.18, 0.9, 0.41, 0, 1)), 
                             .Names = c("Var1", "Var2", "value"), row.names = c(NA, -16L), class = "data.frame")

cor_pval <- dcast(melted_corfinal, Var1~Var2)[, -1]
# Set to NA upper triangle excluding diagonal
cor_pval[upper.tri(cor_pval, diag=F)] <- NA

然后我将其融化并作为第二个值添加到 melted_corfinal

cor_pval_col <- melt(cor_pval)
melted_corfinal$value2 <- cor_pval_col$value
melted_corfinal

现在我们按照您的方式绘制，但是对于 geom_tile 我们使用 value2 和 NA 作为 p 值。然后我们在scale_fill_continuous.

中设置na.value="white"

最后我使用 format

为 0 获得 2 个有效数字

p <- ggplot(melted_corfinal, aes(Var2, Var1)) +
  geom_tile(aes(fill = value2)) +
  scale_fill_continuous("",limits=c(0, 1), breaks=seq(0,1,by=0.2), low = "#fee8c8", high = "#e34a33", na.value = "white") + 
  geom_text(aes(label = format(value, nsmall=2))) +
  theme_light() + theme(legend.position="none",axis.title.x = element_blank(),axis.title.y = element_blank()) +
  guides(fill = guide_colorbar(barwidth = 20)) +
  ylim(rev(levels(melted_corfinal$Var1))) + xlim(levels(melted_corfinal$Var2))
p

仅更改 ggplot2 中热图的上三角矩阵的颜色

Change color only of the upper triangle matrix of a heat map in ggplot2

r

matrix

heatmap

ggplot2