具有两个向量的R着色数据帧

Question

Suppose I have two vectors of the same length, one filled with colors, and another filled with letters.

colors <- c("red","white","blue","green","yellow")
letters <- c("A","B","C","D",E")

What would be the best direction to go about creating a heatmap of sorts, of two rows, where the first row contains each letter, and the next row is a box colored in with the numerically corresponding vector index?

-----------
|A|B|C|D|E|
-----------
|R|W|B|G|Y|     #<---- Colored boxes, not just characters.
-----------

I would like to output this diagram with ggplot but unlike with a heatmap in ggplot, there would be many different colors for many different variables.

Answer 1

I'd do it in ggplot2.

First you need to make colors and letters into an factor, so that the associated orders are preserved.

colors <- c("red","white","blue","green","yellow")
letters <- c("A","B","C","D","E")

colors <- factor(colors, levels = colors)
letters <- factor(letters, levels = letters)

Then you create your own fill palette. Just the same as your colours.

my_fill <- c("red", "white", "blue", "green", "yellow")

Now use geom_raster to make the heatmap and geom_text to place the letters and add your own fill scale.

ggplot(NULL) +
  aes(x = c(1, 2, 3, 1, 2),
      y = c(2, 2, 2, 1, 1),
      fill = colors,
      label = letters) +
  geom_raster() +
  geom_text() +
  scale_fill_manual(values=my_fill)

Is this what you want? It will require a bit of tweaking for repeated colours.

Answer 2

Also in ggplot:

library(ggplot2)


#make data
colors = c("red","white","blue","green","yellow")
names(colors) <- c("A","B","C","D","E")
data <- expand.grid(letters = c("A","B","C","D","E"),y=c(1:2),
                    stringsAsFactors = F)
data$colour <- ifelse(data$y==1,colors[data$letters],"white")
data$label <- ifelse(data$y==1,"",data$letters)

#plot
p1 <- ggplot(data, aes(x=letters,y=y)) + geom_tile(aes(fill=colour),colour="black")+
  scale_fill_identity() + coord_fixed()
p1 + geom_text(aes(label=label)) + theme_minimal() +
  theme(
    axis.text=element_blank(),
    axis.ticks=element_blank(),
    panel.grid=element_blank()
  ) + labs(x="",y="")