向 rgl 3d 绘图添加图例

Question

我正在尝试使用带有颜色图例的 rgl 绘制 3d 图，指示哪种颜色指的是哪个类（称为“cut.rank”）：

plot3d(
data.focus$normalized.price_shipping,
data.focus$seller_feedback_score_rank,
data.focus$seller_positive_feedback_percent_rank, 
col=as.factor(data.focus$cut.rank), 
size=1, 
type='s',
xlab = 'Normalized Price',
ylab = 'Seller Feedbacl Score Rank',
zlab = 'Seller Positive Feedback Percent Rank',
main = 'Rank By Price, Feedback score and Positive Feedback Score',
sub = 'Search Rank has 3 colored levels',
colkey = list(length = 0.5, width = 0.5, cex.clab = 0.75))
) 

但我似乎无法让传说出现在情节中。 （见附图） 有什么想法吗？

Answer 1

我不确定colkey 选项是否适用于plot3d 函数。您可以使用legend3d 来添加图例，就像在普通二维图中一样：

library(rgl)

#dummy data
set.seed(1)
x <- cumsum(rnorm(100))
y <- cumsum(rnorm(100))
z <- cumsum(rnorm(100))
cuts = cut(x = 1:length(x), breaks = 3)

# open 3d window
open3d()

# resize window
par3d(windowRect = c(100, 100, 612, 612))

# plot points
plot3d(x, y, z,
       col=rainbow(3)[cuts], 
       size = 2, type='s')

# add legend
legend3d("topright", legend = paste('Type', c('A', 'B', 'C')), pch = 16, col = rainbow(3), cex=1, inset=c(0.02))

# capture snapshot
snapshot3d(filename = '3dplot.png', fmt = 'png')

更新：colkey 是plot3D 包中scatter3D 的参数（与rgl 包中的plot3d 函数不同）。您也可以使用它：

library(plot3D)
scatter3D(x,y,z, col = rainbow(3)[cuts], colvar = NA, colkey = F, pch = 16)
legend("topright", paste('Type', c("A", "B", "C")), pch = 16, col = rainbow(3), cex=1, inset=c(0.02,0.2))