用表面椭圆在R中绘制Ellipse3d [英] Plotting Ellipse3d in R Plotly with surface ellipse

问题描述

类似于这里的问题，但这并没有给我我所需要的东西，我无法弄清楚:

Similar to the question here but this didn't give me excatly what I needed and I couldn't figure it out: Plot ellipse3d in R plotly?. I want to recreate rgl's ellipse3d and surface ellipsoid in plotly. I know there there was an anwer which allowed plotting of an ellipse but as individual opaque markers, I need to get it as a surface ellipsoid that's slightly opaque so I can still see the data points in the ellipsoid.

我试图弄清楚dww对"add_surface"的评论是如何工作的，但无法弄清楚…….有人可以帮忙吗?

I tried to figure out how dww's comment for "add_surface" instead works but couldn't figure it out.... Can anyone help please?

if (!require("rgl")) install.packages("rgl")
dt <- cbind(x = rnorm(100), y = rnorm(100), z = rnorm(100))
ellipse <- ellipse3d(cov(dt))
plot3d(dt)
plot3d(ellipse, add = T, color = "red", alpha = 0.5)

dww的答案是:

if (!require("plotly")) install.packages("plotly")
if (!require("rgl")) install.packages("rgl")
dt <- cbind(x = rnorm(100), y = rnorm(100), z = rnorm(100))
ellipse <- ellipse3d(cov(dt))

p <- plot_ly(mode = 'markers') %>% 
  add_trace(type = 'scatter3d', size = 1, 
  x = ellipse$vb[1,], y = ellipse$vb[2,], z = ellipse$vb[3,], 
  opacity=0.01) %>% 
  add_trace(type = 'scatter3d', x = dt[,1], y = dt[,2], z = dt[,3])
p

# shows more obviously what dww's code does to create the visual ellipsoid
w <- plot_ly(mode = 'markers') %>% 
  add_trace(type = 'scatter3d',  
  x = ellipse$vb[1,], y = ellipse$vb[2,], z = ellipse$vb[3,], 
  opacity=0.5) %>% 
  add_trace(type = 'scatter3d', x = dt[,1], y = dt[,2], z = dt[,3])
w

他们关于如何使用add_surface的评论

Their comment on how to use add_surface was

请注意，为简单起见，我使用标记将椭圆形绘制为云形.如果要使用add_surface，则必须首先将椭圆转换为另一种格式，以x位置的向量，y位置的向量，z作为矩阵(尺寸等于x乘以y).您还需要将z值分成两个单独的表面层，一个用于椭圆形的上半部，另一个用于下半部.我现在没有时间做所有这些事情，但是如果您遇到困难，可以稍后再解决

Note that for simplicity, I plotted the ellipse as a cloud using markers. If you want to use add_surface instead, you will have to first convert the ellipse into a different format, with a vector of x locations, a vector of y locations, z as a matrix (dimensions equal to x by y). You'll also need to split the z values into two separate surface layers one for the top half of the ellipsoid and one for the bottom. I don't have time right now to do all this, but if you get stuck I can work this out later

推荐答案

如果有人对此感兴趣，这就是我的解决方案.这样就可以使用图中的按钮来切换椭圆体的打开和关闭，以便您仍可以在需要时悬停并选择椭圆体内的数据点:

This is my solution if anyone is interested in it. This allows using of the buttons in plotly to toggle the ellipsoid on and off so that you can still hover over and select data points inside the ellipsoid when desired:

if (!require("rgl")) install.packages("rgl", dependencies=TRUE, repos="http://cran.rstudio.com/")
if (!require("plotly")) install.packages("plotly", dependencies=TRUE, repos="http://cran.rstudio.com/")    
dt <- cbind(x = rnorm(100), y = rnorm(100), z = rnorm(100))
ellipse <- ellipse3d(cov(dt))

updatemenus <- list(
  list(
    active = 0,
    type= 'buttons',
    buttons = list(
      list(
        label = "Ellipsoid",
        method = "update",
        args = list(list(visible = c(TRUE, TRUE)))),
      list(
        label = "No Ellipsoid",
        method = "update",
        args = list(list(visible = c(TRUE, FALSE)))))
  )
)

plot<- plot_ly()%>%
  # Plot raw scatter data points
  add_trace(data = dt, x = dt[,1], y = dt[,2], z = dt[,3],
            type = "scatter3d", mode = 'markers', marker = list(size = 3))  %>%
  # Plot ellipsoid 
  add_trace(x=ellipse$vb [1,], y=ellipse$vb [2,], z=ellipse$vb [3,], 
            type='mesh3d', alphahull = 0, opacity = 0.4)%>%
  # Axes Titles
  layout(updatemenus = updatemenus)
plot

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