R-我如何将 3D 散点 plot 展平为二维 plot？

Question

我已经使用scatter3D()将数据（来自 a.csv 文件）绘制到 3D scatter plot 中。 I want to turn this into a 2-D plot, where the colour of each of the plotted points is the same as it is in the 3D plot -ie I want a 2D projection of my currently 3D scatter plot with the same colour scheme for所有点和以前一样（基于 z 值）。

我该如何 go 关于这个？

或者 - 有没有办法可以 plot 二维图形，z 值指示绘制在 (x,y) 处的点的颜色？

Answer 1

如果您的z变量是一个因素（类别）：

library(ggplot)
df <- data.frame(x = 1:18, y = runif(18), z = c('A', 'B', 'C'))    
ggplot(df, aes(x, y)) +
    geom_point(aes(color = z)) +
    # optional
    scale_color_manual(values = c('red', 'blue', 'green'))

如果您的z变量是连续变量：

library(ggplot2)
df <- data.frame(x = 1:18, y = runif(18), z = runif(18, min = 1, max = 100))
ggplot(df, aes(x, y)) +
    geom_point(aes(color = z)) +
    # optional
    scale_color_continuous(low = 'red', high = 'green')