R 带字符串的图形-边必须是数字或字符

下面是一些用于生成显示生成的层次结构的图形的代码，但它不显示并返回以下错误：

图形（设备）中出错：“边”必须是数字或字符

代码如下：

library(igraph)

# n = num of field devices
generate_hierarchy <- function(n=100, levels=3) {
  k <- c()
  for(i in 0:n) {
    curDevice <- paste("device", i)
    # For lower levels, generate 1-2 parent units
    for(j in 0:levels) {
      p = sample(1:2, 1)
      for(k in 0:p) {
        k <- c(k, c(curDevice, paste("unit", k, j)))
      }
    }
  }
  return(devices)
}



### Generate ###

field_devices <- 100
levels <- 2*log10(field_devices)

devices <- generate_hierarchy(field_devices, levels)
print(devices)

# Creeate basic graph
g <- graph(devices)
plot(g, vertex.color = "lightcoral", vertex.size = 40, edge.color='indianred4')

库（igraph）
#n=现场设备的数量
生成层次结构运行示例时出现的错误是

Error in generate_hierarchy(field_devices, levels) : 
  object 'devices' not found

如果将return语句更改为
return（k）
，则我可以无错误地运行代码，并可以看到绘图：

generate_hierarchy <- function(n=100, levels=3) {
  k <- c()
  for(i in 0:n) {
    curDevice <- paste("device", i)
    # For lower levels, generate 1-2 parent units
    for(j in 0:levels) {
      p = sample(1:2, 1)
      for(k in 0:p) {
        k <- c(k, c(curDevice, paste("unit", k, j)))
      }
    }
  }
  return(k)
}

field_devices <- 100
levels <- 2*log10(field_devices)

devices <- generate_hierarchy(field_devices, levels)
[enter image description here][1]
g <- graph(devices)
plot(g, vertex.color = "lightcoral", vertex.size = 40, edge.color='indianred4')

generate\u层次结构谢谢！我不知道我怎么没注意到：）有没有办法让它成为一个树结构？我将
k
重命名为设备，因为for循环中使用了
k
。因此，添加链接就变成了
设备
generate_hierarchy <- function(n=100, levels=3) {
  k <- c()
  for(i in 0:n) {
    curDevice <- paste("device", i)
    # For lower levels, generate 1-2 parent units
    for(j in 0:levels) {
      p = sample(1:2, 1)
      for(k in 0:p) {
        k <- c(k, c(curDevice, paste("unit", k, j)))
      }
    }
  }
  return(k)
}

field_devices <- 100
levels <- 2*log10(field_devices)

devices <- generate_hierarchy(field_devices, levels)
[enter image description here][1]
g <- graph(devices)
plot(g, vertex.color = "lightcoral", vertex.size = 40, edge.color='indianred4')