r - 散点图3d : regression plane with residuals

Question

使用scatterplot3d在 R 中，我试图从观察到回归平面绘制红线:

wh <- iris$Species != "setosa"
x  <- iris$Sepal.Width[wh]
y  <- iris$Sepal.Length[wh]
z  <- iris$Petal.Width[wh]
df <- data.frame(x, y, z)

LM <- lm(y ~ x + z, df)
library(scatterplot3d)
G  <- scatterplot3d(x, z, y, highlight.3d = FALSE, type = "p")
G$plane3d(LM, draw_polygon = TRUE, draw_lines = FALSE)

要获取以下图片的 3D 等效内容:

在 2D 中，我可以使用 segments :

pred  <- predict(model) 
segments(x, y, x, pred, col = 2)

但是在 3D 中我对坐标感到困惑。

Answer 1

我决定也包含我自己的实现，以防其他人想要使用它。

回归平面

require("scatterplot3d")

# Data, linear regression with two explanatory variables
wh <- iris$Species != "setosa"
x  <- iris$Sepal.Width[wh]
y  <- iris$Sepal.Length[wh]
z  <- iris$Petal.Width[wh]
df <- data.frame(x, y, z)
LM <- lm(y ~ x + z, df)

# scatterplot
s3d <- scatterplot3d(x, z, y, pch = 19, type = "p", color = "darkgrey",
                     main = "Regression Plane", grid = TRUE, box = FALSE,  
                     mar = c(2.5, 2.5, 2, 1.5), angle = 55)

# regression plane
s3d$plane3d(LM, draw_polygon = TRUE, draw_lines = TRUE, 
            polygon_args = list(col = rgb(.1, .2, .7, .5)))

# overlay positive residuals
wh <- resid(LM) > 0
s3d$points3d(x[wh], z[wh], y[wh], pch = 19)

残差

# scatterplot
s3d <- scatterplot3d(x, z, y, pch = 19, type = "p", color = "darkgrey",
                     main = "Regression Plane", grid = TRUE, box = FALSE,  
                     mar = c(2.5, 2.5, 2, 1.5), angle = 55)

# compute locations of segments
orig     <- s3d$xyz.convert(x, z, y)
plane    <- s3d$xyz.convert(x, z, fitted(LM))
i.negpos <- 1 + (resid(LM) > 0) # which residuals are above the plane?

# draw residual distances to regression plane
segments(orig$x, orig$y, plane$x, plane$y, col = "red", lty = c(2, 1)[i.negpos], 
         lwd = 1.5)

# draw the regression plane
s3d$plane3d(LM, draw_polygon = TRUE, draw_lines = TRUE, 
            polygon_args = list(col = rgb(0.8, 0.8, 0.8, 0.8)))

# redraw positive residuals and segments above the plane
wh <- resid(LM) > 0
segments(orig$x[wh], orig$y[wh], plane$x[wh], plane$y[wh], col = "red", lty = 1, lwd = 1.5)
s3d$points3d(x[wh], z[wh], y[wh], pch = 19)

<小时/>

最终结果:

虽然我非常欣赏 scatterplot3d 函数的便利性，但最终我得到了 copying the entire function from github ，因为基 plot 中的几个参数要么被 scatterplot3d 强制，要么没有正确传递给 scatterplot3d(例如，使用 las 进行轴旋转，使用 las 进行字符扩展) cex、cex.main 等)。我不确定这么长而困惑的代码块放在这里是否合适，所以我在上面添加了 MWE。

无论如何，这就是我最终在我的书中包含的内容:

(是的，这实际上只是虹膜数据集，不要告诉任何人。)