带有连续彩虹色的热图 [英] Heatmap with continuous rainbow colours

问题描述

首先，我不得不说，我在stackoverflow和其他地方阅读了许多有关heatmap和ggplot2的主题.但是我的问题还没有解决.

First of all I have to say that I read many threads about heatmap and ggplot2 here in stackoverflow and elsewhere. But my problem isn't solved yet.

我有以下数据集:

   Var1   Var2 value
1 -197.5 -197.5     0
2 -192.5 -197.5     0
3 -187.5 -197.5     0
4 -182.5 -197.5     0
5 -177.5 -197.5     0
6 -172.5 -197.5     0
.....

该值应该是颜色，并且右侧的图例会很好.

The value should be the colour, and a legend on the right side would be nice.

library(ggplot2)
ggheatmap <- ggplot(data = dat.plot, aes(x=Var1, y=Var2, fill=value)) + 
  geom_raster()+
  scale_fill_gradientn(colours=rainbow(100))+
  theme(axis.text.x = element_text(angle = 0))+ 
  coord_fixed()
print(ggheatmap)

结果是:

我希望有一个正常"的彩虹标度，从红色=高到橙色，黄色，绿色，浅蓝色，深蓝色=低，而没有给出固定的离散颜色，例如使用scale_fill_gradient2. 我不知道为什么彩虹"以红色=高端以其他红色结尾...

I would like to have a "normal" rainbow scale from red=high over orange, yellow, green, light blue, dark blue=low without giving fixed discrete colours as one can do it, e.g. with scale_fill_gradient2. I wonder why "rainbow" starts with red=high end ends with some other red...

另一个问题:我如何添加一些东西来平滑"热图，以使人到处都看不到边缘"?

The other question: How can I add something to "smooth" the heatmap so that one doesn't see the "edges" everywhere?

推荐答案

简短答案:函数rainbow() 发疯了当您通过100时，您要求使用100不同的颜色

Short answer: function rainbow() goes nuts when you pass 100 as you're asking for 100 different colors.

您应该做什么:将n传递给rainbow()以获取所需的颜色数.如果要从蓝色变为红色，则还必须使用功能rev()将其包装.

What should you do: pass n to rainbow() for how many colors you want. If you want to go from blue to red then you also have to wrap it with function rev().

library(egg)
library(ggplot2)
library(reshape2)

# Heatmap number of rows/columns
Nvalue <- 1e2
# n for colors passed to function rainbow
nColor <- c(1:10, seq(20, 100, 20))
# dummy data
df <- melt(matrix(rnorm(N^2), N))

plotList <- list()
for(i in seq_along(nColor)) {
    plotList[[i]] <- ggplot(df, aes(Var1, Var2, fill = value)) + 
        geom_raster() +
        scale_fill_gradientn(colours = rev(rainbow(nColor[i]))) +
        labs(title = paste0("rainbow(", nColor[i], ")"),
             x = NULL,
             y = NULL,
             fill = NULL) +
        theme_void()
}

ggarrange(plots = plotList)

在他指定了OP指定的颜色之后，则可以通过十六进制矢量:

After OP specified colors he wants then passing hex vector should work:

hex <- c("#FF0000", "#FFA500", "#FFFF00", "#008000", "#9999ff", "#000066")
ggplot(df, aes(Var1, Var2, fill = value)) + 
        geom_raster() +
        scale_fill_gradientn(colours = rev(hex)) +
        labs(x = NULL,
             y = NULL,
             fill = NULL) +
        theme_void()

这篇关于带有连续彩虹色的热图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！