意想不到的行为与plot3d和knitr绘图传说

Question

我想用两个3d散点图使用rgl使用knitr生成一个html文档，但我尝试将图例添加到这两个图时有问题。使用完全相同的代码（从一个块复制并粘贴到另一个块，然后更改要绘制的值），第一个图的图例以HTML方式显示得太大。我已经生成了一个与我正在使用的数据类似的示例脚本：

--- 
title: "example" 
output: html_document 
--- 

Example script 

# First plot 
```{r 1st chunk, webgl=TRUE, echo = FALSE, fig.width=10, fig.height=10} 
library(rgl) 
knitr::knit_hooks$set(webgl = hook_webgl) 
dt <- data.frame(x = runif(70, min = 1, max = 10), 
       y = runif(70, min = -10, max = 1), 
       z = runif(70, min = -20, max = -10), 
       groups = rep(c("Group1", "Group2", "Group3", "Group4", "Group5", "Group6", "Group7"), each = 10)) 
plot3d(dt$x, dt$y, dt$z, 
     xlab = "X", ylab = "Y", zlab = "Z", 
     type ="n") 
grid3d(c("x", "y+", "z")) 
legend3d("bottomright", 
     c("Group1", "Group2", "Group3", "Group4", "Group5", "Group6", "Group7"), 
     col = c(1:7), 
     pch = 20, 
     bg = "black", 
     bty = "n", 
     y.intersp = 0.8, 
     cex = 1.5) 
for (i in seq_along(unique(dt$groups))){ 
    sub <- dt[dt$groups == unique(dt$groups)[i],] 
    pch3d(sub$x, sub$y, sub$z, 
     col = i, 
     pch = 16, 
     radius = 0.2, 
     add = T)} 
``` 

This first legend is way too large, while, with the exame same code, for the next plot, the legend is normal size 

# Second plot 
```{r 2nd chunk, webgl=TRUE, echo = FALSE, fig.width=10, fig.height=10} 
library(rgl) 
knitr::knit_hooks$set(webgl = hook_webgl) 
dt <- data.frame(x = runif(150, min = 2, max = 20), 
       y = runif(150, min = -20, max = 2), 
       z = runif(150, min = -30, max = -20), 
       groups = rep(c("Group1", "Group2", "Group3", "Group4", "Group5", "Group6", "Group7", "Group8", 
           "Group9", "Group10", "Group11", "Group12", "Group13", "Group14", "Group15"), each = 10)) 
plot3d(dt$x, dt$y, dt$z, 
     xlab = "X", ylab = "Y", zlab = "Z", 
     type ="n") 
grid3d(c("x", "y+", "z")) 
legend3d("bottomright", 
     c("Group1", "Group2", "Group3", "Group4", "Group5", "Group6", "Group7", "Group8", 
     "Group9", "Group10", "Group11", "Group12", "Group13", "Group14", "Group15"), 
     col = c(1:15), 
     pch = 20, 
     bg = "black", 
     bty = "n", 
     y.intersp = 0.8, 
     cex = 1.5) 
for (i in seq_along(unique(dt$groups))){ 
    sub <- dt[dt$groups == unique(dt$groups)[i],] 
    pch3d(sub$x, sub$y, sub$z, 
     col = i, 
     pch = 16, 
     radius = 0.2, 
     add = T)} 
``` 

任何帮助将不胜感激！

Answer 1

这有点奇怪，我看了一下，发现legend3d调用中cex参数（意思是“字符扩展”）在某种程度上在呼叫调用中有不同的解释。看起来像一个小错误。

但是我也发现你可以通过在每个plot之前加上open3d命令来修复它。也许这是一个修复？

代码：

--- 
title: "example" 
output: html_document 
--- 

Example script 

```{r 0th chunk, webgl=TRUE, echo = FALSE} 
library(rgl) 
knitr::knit_hooks$set(webgl = hook_webgl) 
``` 

# First plot 


```{r 1st chunk, webgl=TRUE, echo = FALSE, fig.width=5, fig.height=5} 
glob_cex <- 0.6 

open3d() 
dt <- data.frame(x = runif(70, min = 1, max = 10), 
       y = runif(70, min = -10, max = 1), 
       z = runif(70, min = -20, max = -10), 
       groups = rep(c("Group1", "Group2", "Group3", "Group4", "Group5", "Group6", "Group7"), each = 10)) 
plot3d(dt$x, dt$y, dt$z, 
     xlab = "X", ylab = "Y", zlab = "Z", 
     type ="n") 
grid3d(c("x", "y+", "z")) 
legend3d("bottomright", 
     c("Group1", "Group2", "Group3", "Group4", "Group5", "Group6", "Group7"), 
     col = c(1:7), 
     pch = 20, 
     bg = "black", 
     bty = "n", 
     y.intersp = 0.8, 
     cex = 0.8) 
for (i in seq_along(unique(dt$groups))){ 
    sub <- dt[dt$groups == unique(dt$groups)[i],] 
    pch3d(sub$x, sub$y, sub$z, 
     col = i, 
     pch = 16, 
     radius = 0.2, 
     add = T)} 
``` 

Legends are now the same size by adding an open3d() command before each plot. 

# Second plot 
```{r 2nd chunk, webgl=TRUE, echo = FALSE, fig.width=5, fig.height=5} 
open3d() 
dt <- data.frame(x = runif(150, min = 2, max = 20), 
       y = runif(150, min = -20, max = 2), 
       z = runif(150, min = -30, max = -20), 
       groups = rep(c("Group1", "Group2", "Group3", "Group4", "Group5", "Group6", "Group7", "Group8", 
           "Group9", "Group10", "Group11", "Group12", "Group13", "Group14", "Group15"), each = 10)) 
plot3d(dt$x, dt$y, dt$z, 
     xlab = "X", ylab = "Y", zlab = "Z", 
     type ="n") 
grid3d(c("x", "y+", "z")) 
legend3d("bottomright", 
     c("Group1", "Group2", "Group3", "Group4", "Group5", "Group6", "Group7", "Group8", 
     "Group9", "Group10", "Group11", "Group12", "Group13", "Group14", "Group15"), 
     col = c(1:15), 
     pch = 20, 
     bg = "black", 
     bty = "n", 
     y.intersp = 0.8, 
     cex = 0.8) 
for (i in seq_along(unique(dt$groups))){ 
    sub <- dt[dt$groups == unique(dt$groups)[i],] 
    pch3d(sub$x, sub$y, sub$z, 
     col = i, 
     pch = 16, 
     radius = 0.2, 
     add = T)} 
``` 

屏幕截图：

Answer 2

我建议您不要使用webgl=TRUE，把一个rglwidget()呼叫在底部。这使得文本太大，因为它从256x256的小窗口放大;使用r3dDefaults$windowRect <- c(0,0,1000,1000)（或类似的大值）来获得更好的尺寸。

您可能还想在开始时使用options(rgl.useNULL = TRUE)，因此编织时不会弹出窗口。这有一个副作用，允许您将r3dDefaults$windowRect值设置为比物理屏幕更大的值。

r3dDefaults$windowRect和options("rgl.useNULL")值应该只需要在文档顶部附近设置一次，除非您明确更改它们，否则将应用于以下所有图。