简介和使用

我们需要下载一下这个包：

install.packages('RColorBrewer')

使用包中的函数brewer.pal() 可以创建一个颜色值的向量，n 指定从颜色盘中取得的数目，name 指定颜色盘：

> library(RColorBrewer)
> mycolor = brewer.pal(7, 'Set1')
> mycolor
[1] "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00" "#FFFF33" "#A65628"

可以看看这些颜色：

> barplot(rep(1,7), col = mycolor)

我们还可以看看包中的所有颜色：

library(RColorBrewer)
display.brewer.all()

按照官方的介绍，RColorBrewer 上面这三类调色板各有应用：

Sequential palettes (first list of colors): 适合单一方向变化的连续性变量，names are : Blues, BuGn, BuPu, GnBu, Greens, Greys, Oranges, OrRd, PuBu, PuBuGn, PuRd, Purples, RdPu, Reds, YlGn, YlGnBu YlOrBr, YlOrRd
Qualitative palettes (second list of colors): 适合分类变量，names are : Accent, Dark2, Paired, Pastel1, Pastel2, Set1, Set2, Set3.
Diverging palettes (third list of colors): 由中间向两侧变化的连续性变量，names are : BrBG, PiYG, PRGn, PuOr, RdBu, RdGy, RdYlBu, RdYlGn, Spectral



重要函数

function arguments:
n: Number of different colors in the palette, minimum 3, maximum depending on palette.
name: A palette name from the lists above. For example name = RdBu.
type: The type of palette to display. Allowed values are one of: “div”, “qual”, “seq”, or “all”.
select: A list of palette names to display.
colorblindFriendly: if TRUE, display only colorblind friendly palettes.

获得对应调色板对应数目颜色的十六进制数值：

brewer.pal(n, name)
brewer.pal(3, "OrRd")
[1] "#FEE8C8" "#FDBB84" "#E34A33"

展示某个调色板的对应数目颜色（其实也可以自己画柱状图实现类似）：

display.brewer.pal(3, "OrRd")

展示部分或全部颜色， 这点吹爆啊，还有一个参数colorblindFriendly 可以选择是否只出现对色盲友好的颜色：

display.brewer.all(n = NULL, type = "all", select = NULL,
                   colorblindFriendly = T)

总结

Sequential palettes (first list of colors): 适合单一方向变化的连续性变量，names are : Blues, BuGn, BuPu, GnBu, Greens, Greys, Oranges, OrRd, PuBu, PuBuGn, PuRd, Purples, RdPu, Reds, YlGn, YlGnBu YlOrBr, YlOrRd
Qualitative palettes (second list of colors): 适合分类变量，names are : Accent, Dark2, Paired, Pastel1, Pastel2, Set1, Set2, Set3.
Diverging palettes (third list of colors): 由中间向两侧变化的连续性变量，names are : BrBG, PiYG, PRGn, PuOr, RdBu, RdGy, RdYlBu, RdYlGn, Spectral