visNetwork当尝试在 for 循环中显示时，My根本不显示。在常规 R 脚本中，我使用该print函数并且它工作得很好，但它在 R Markdown 文档中不起作用。
这是一个（希望）可重现的示例：
---
title: "I want my beautiful networks back!"
---
# First example that works
```{r}
require(visNetwork, quietly = TRUE)
# minimal example
nodes <- data.frame(id = 1:3)
edges <- data.frame(from = c(1,2), to = c(1,3))
vn <- visNetwork(nodes, edges, width = "100%")
vn # Or print(vn)
```
# When does it not work?
## In a for loop
```{r}
for (i in 1) vn
```
## In a …我想制作一个cumsum多矩阵来获取步骤.如果我们考虑:
A <- structure(c(1, 2, 3, 2, 3, 1, 4, 1, 2), .Dim = c(3, 3))
# [,1] [,2] [,3]
# [1,] 1 2 4
# [2,] 2 3 1
# [3,] 3 1 2
B <- structure(c(6, 1, 9, 6, 3, 7, 3, 2, 8), .Dim = c(3, 3))
# [,1] [,2] [,3]
# [1,] 6 6 3
# [2,] 1 3 2
# [3,] 9 7 8
C <- structure(c(1, 1, 2, 5, 3, 3, 3, …