使用粘贴语句创建 data.frame 列

Question

我有一个 Current dataFrame，例如：

BaseTable
S.no.  Category    First  Second  Third
1      Abc Class    10     12      3
2      Xyz Class    12      3      4
3      asd Class    10      2      4

现在，我想在 data.frame 中使用 paste 语句在此数据框中添加一列。我试过用assign() 和noquotes() 来做，但是用那个名字创建了一个新变量。

First = unique(BaseTable$First)
Count = 1    
Combinations = c('First', 'Second', 'Third')
For(i in combinations){
   assign(paste("BaseTable$no", Count, "[BaseTable$", i ," %in% ", i[j], "]", sep = ''), j)
   Count = Count +1
}

我得到的输出是一个变量名BaseTable$no10[BaseTable$Perfect %in% Perfect] 其次，这里i 是一个具有多个元素的向量，但是使用粘贴语句，它将i[j] 值显示为NA。 喜欢First[1] = NA。

我想要输出如下：

BaseTable
S.no.  Category    First  Second  Third  No1   No2   No3
1      Abc Class    10     12      3      1     1     1
2      Xyz Class    12      3      4      2     2     2
3      asd Class    10      2      4      1     3     2

Answer 1

解决方案在这里How to create an index from a variable in a dataframe

BaseTable$No1 <- as.numeric(factor(BaseTable$First))
BaseTable$No2 <- as.numeric(factor(BaseTable$Second))
BaseTable$No3 <- as.numeric(factor(BaseTable$Third))

循环：

combinations = c('First', 'Second', 'Third')
count = 1

for (i in combinations) {

  BaseTable[[paste("No", Count, sep="")]] <- match(BaseTable[[i]], unique(BaseTable[[i]])) # same order
  #BaseTable[[paste("No", Count, sep="")]] <- as.numeric(factor(BaseTable[[i]])) # new order
  count = count +1
}