绘制无点回归平面-R

Question

dat <- data.frame(nitrogen = runif(50, 0, 10), temperature= rnorm(50, 10, 3))
modmat <- model.matrix(~ nitrogen * temperature, dat)
coeff <- c(1, 2, -1, 1.5)
dat$soil <- rnorm(50, mean = modmat %*% coeff, sd = 0.5)

我正在尝试绘制回归平面，以显示temperature如何缓和nitrogen和soil之间的关系。

library(plot3D)

x <- dat$nitrogen
y <- dat$temperature
z <- dat$soil

fit <- lm(z ~ x*y)

grid.lines = 26
x.pred <- seq(min(x), max(x), length.out = grid.lines)
y.pred <- seq(min(y), max(y), length.out = grid.lines)
xy <- expand.grid( x = x.pred, y = y.pred)
z.pred <- matrix(predict(fit, newdata = xy), 
                 nrow = grid.lines, ncol = grid.lines)

fitpoints <- predict(fit)

scatter3D(x, y, z, pch = 18, cex = 2, 
    theta = 20, phi = 20, ticktype = "detailed",
    xlab = "nitrogen", ylab = "soil", zlab = "temperature",  
    surf = list(x = x.pred, y = y.pred, z = z.pred,  
    facets = NA, fit = fitpoints), main = "dat")

这将绘制带有点的回归平面，但是我想绘制没有点的回归平面。调用x, y, z函数时省略scatter3D会导致错误。

Answer 1

这是一个疯狂的主意。尝试设置cex = 0。

scatter3D(x, y, z, pch = 18, cex = 0, 
    theta = 20, phi = 20, ticktype = "detailed",
    xlab = "nitrogen", ylab = "soil", zlab = "temperature",  
    surf = list(x = x.pred, y = y.pred, z = z.pred,  
    facets = NA, fit = fitpoints), main = "dat")