基于其值的矩阵中的颜色编号

Question

我有一个2乘2的矩阵，我想根据它们的值对数字进行着色（比如我的数字从0到20，我想要颜色0-2 =蓝色; 2-4 =天蓝色.. 12-14 =黄色，18-20 =红色等。在Excel中，我只能使用条件格式选项获得3种颜色（参见图）。任何人都知道我是否可以在另一个程序中拥有更多颜色（最好是R）。谢谢！

PS：请注意，我本身不需要热图或等高线图，因为我对数字的确切值感兴趣。

Answer 1

这是一个解决方案，我希望它有所帮助

# you need this for the colour ramp
library(RColorBrewer)

# setup
rows <- 10
collumns <- 10

# data matrix
zVals <- round(rnorm(rows*collumns), 2)
z <- matrix(zVals, rows, collumns)

# pick the number of colours (granularity of colour scale)
nColors <- 100

# create the colour pallete
cols <-colorRampPalette(colors=c("blue", "grey", "red"))(nColors)

# get a zScale for the colours
zScale <- seq(min(z), max(z), length.out = nColors)

# function that returns the nearest colour given a value of z
findNearestColour <- function(x) {
        colorIndex <- which(abs(zScale - x) == min(abs(zScale - x)))
        return(cols[colorIndex])
}

# empty plot
plot(1, 1, type = "n", xlim = c(1, rows), ylim = c(1, collumns), 
     axes = F, xlab = "", ylab = "")

# populate it with the data
for(r in 1:rows){
    for(c in 1:collumns){
        text(c, r, z[c,r], col = findNearestColour(z[c,r])) 
    }
}