scatter3d-基于第四个变量的色点

Question

我想用scatter3d绘制3D图，但不知道如何根据第四个变量（此处为VAR4）的值对点进行着色。有人可以帮我吗？如果添加这些颜色，我仍然保留默认版本中的淡入淡出效果（3D图中越远的点显示的颜色越浅），那就太好了。谢谢！

df <- data.frame(VAR4=c(10,52,78,34,13,54), 
                   A=c(12, 8, 10, 7, 13, 15), 
                   B=c(4,3,2,1,7,5), 
                   C=c(1,3,2,1,3,1))

library(rgl)
library(car)
scatter3d(A ~B + C,color=VAR4, data=df,  surface=F)

Answer 1

您可以尝试以下方法：

library(rgl)
library(car)
# add as group the VAR4, making as factor
scatter3d(A ~B + C, groups = as.factor(df$VAR4), data=df,  surface=F)

但是，如果我能为您提供建议，那么使用plotly软件包会更漂亮，更好：

library(plotly)
# in this case we use VAR4 as continuous, you can put color = ~as.factor(VAR4) to have it as factors
plot_ly(df, x = ~A, y = ~B, z = ~C, color = ~VAR4) %>%
  add_markers() %>%
  layout(scene = list(xaxis = list(title = 'A'),
                      yaxis = list(title = 'B'),
                      zaxis = list(title = 'C')))