Question

我有一个名为mergedColors的颜色列表。从这个颜色列表中，我使用for()循环来创建一个与每种独特颜色相对应的矩阵。到目前为止，一切正常。然后，我想在最初创建矩阵后继续更改/编辑循环中的矩阵。在示例中，我尝试更改第三列的名称。但是，我并不完全确定如何去做。当我尝试通过我用来创建它们的相同语法来调用它们时，

colnames(paste("merged",each,sep="_"))[3] = "Temp"

R返回错误：＆＃34;赋值目标扩展为非语言对象＆＃34;。如何在循环内部调用我刚刚创建的矩阵？

示例数据：

mergedColors = c("red", "blue", "green", "red", "black", "blue", "blue", "green", "yellow", "red")
table(mergedColors)



for(each in unique(mergedColors)){ 

  assign(paste("merged",each,sep="_"), as.matrix(cbind(cars, c(each))))
  #colnames(paste("merged",each,sep="_"))[3] = "Temp"

}

Answer 1

您只需要使用get告诉R您要粘贴的内容是指对象。

像这样：

tmp <- get(paste("merged",each,sep="_"))
colnames(tmp)[3] = "Temp"

> head(tmp)
     speed dist  Temp    
[1,] " 4"  "  2" "yellow"
[2,] " 4"  " 10" "yellow"
[3,] " 7"  "  4" "yellow"
[4,] " 7"  " 22" "yellow"
[5,] " 8"  " 16" "yellow"
[6,] " 9"  " 10" "yellow"

这是完整循环：

for(each in unique(mergedColors)){ 

  assign(paste("merged",each,sep="_"), as.matrix(cbind(cars, c(each))))
  #colnames(paste("merged",each,sep="_"))[3] = "Temp"
  tmp <- get(paste("merged",each,sep="_"))
  colnames(tmp)[3] = "Temp"
  assign(paste("merged",each,sep="_"), tmp)

}

调用在for（）循环

1 个答案: