r ggplot geom_point更改颜色 [英] r ggplot geom_point change color

问题描述

我正在运行代码，它可以正常工作

I am running the code and it works

ggplot(data_df, aes(x= RR, y= PPW, col = year)) + 
  geom_point(size = 3, alpha=0.6)

现在，我试图将(x，y)的平均值放在图形上，通过添加使其具有另一种颜色

Now I am trying to put the mean value of (x,y) on graph en give it another color by adding

ggplot(data_df, aes(x= RR, y= PPW, col = year))) + 
  geom_point(size = 3, alpha=0.6) + 
  geom_point(data=data_df, aes(x=mean(RR), y=mean(PPW)) + 
  geom_point(color="red")

可以，但是所有点的颜色现在都是红色

It works, but the color of all points is now red

如果我将颜色放在这样的aes中，则平均点会得到另一种颜色，我也可以在图例中看到它

If I put color inside aes like these, the mean point get another color, and I see it also in legend

ggplot(data_df, aes(x= RR, y= PPW, col = year))) + 
  geom_point(size = 3, alpha=0.6) + 
  geom_point(data=data_df, aes(x=mean(RR), y=mean(PPW), color="red"))

我想手动给颜色.有可能吗?

I would like to give the color manually. Is it possible?

推荐答案

您缺少有关ggplot如何管理美学的两个关键点:

You're missing two key points about how ggplot manages aesthetics:

1. 每个geom_*层都将从父ggplot调用中继承aes设置，除非您手动覆盖它.因此，在您的第一个示例中，第三个geom_point继承了ggplot的x和y值，而不是其上方的均值"层，因此在每个有色点的上方都呈现了一个红色点.

1. Each geom_* layer will inherit the aes settings from the parent ggplot call, unless you manually override it. So in you first example, the 3rd geom_point inherits the x and y values from ggplot, not the "mean" layer above it, and thus renders a red point on top of each colored point.

aes中的值应用于刻度，不按原样使用.因此，在第二个示例中，将color = 'red'放在aes中时，并不是将点设为红色，而是说颜色应由类别变量确定(这里是长度1的向量，包括单词"red")基于scale_color_*.您可以添加scale_color_manual并设置'red' = 'red'，以便该值呈现所需的颜色，也可以将color=移动到aes之外，以便按原样进行解释(并将该层中的所有点设为红色).

Values in the aes are applied to a scale, not used as is. So when you put color = 'red' in the aes in your second example, you aren't making the points red, you're saying that color should be determined by a categorical variable (which here is a length 1 vector consisting of the word 'red') based on the scale_color_*. You can either add a scale_color_manual and set 'red' = 'red', so that value renders the desired color, or move the color= outside the aes, so it is interpreted as is (and will make all points in that layer red).

---

记住这些要点，做您想做的事情就像将color移到aes之外一样简单:

---

With those points in mind, doing what you want is as simple as moving the color outside the aes:

ggplot(data_df, aes(x= RR, y= PPW, col = year))) + 
    geom_point(size = 3, alpha=0.6) + 
    geom_point(data=data_df, aes(x=mean(RR), y=mean(PPW)), color="red")

这篇关于r ggplot geom_point更改颜色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！