4
我想要在三维散点图中关于主要成分(主要成分作为这些椭圆的轴)可视化浓度椭球。我用选项椭圆函数scatter3d = TRUE将点和线添加到R中的三维散点图
data3d <- iris[which(iris$Species == "versicolor"), ]
library(car)
library(rgl)
scatter3d(x = data3d[,1], y = data3d[,2], z = data3d[,3],
surface=FALSE, grid = TRUE, ellipsoid = TRUE,
axis.col = c("black", "black", "black"), axis.scales = FALSE,
xlab = "X1", ylab = "X2", zlab = "X3", surface.col = "blue",
revolution=0, ellipsoid.alpha = 0.0, level=0.7, point.col = "yellow", add=TRUE)
作出这样的情节:
然后我试图加入 “中间点” 使用
points3d(mean(data3d[,1]), mean(data3d[,2]), mean(data3d[,3]), col="red", size=20)
但这点不在它应该在的位置(在椭球体的中心):
我想知道为什么以及如何重新调整它(?)。还有另一个问题,在这之后会出现如何将这个椭球的坐标轴添加到图中?
'par3d()'表示该框已缩放为单位立方体? –