r - 如果满足语句，如何在数据集中插入带有值的新列

Question

我有一个大型数据集，并且希望在数据集中插入一个包含二进制值(0 和 1)的新列(如果它满足以下条件)。

如果列包含 df1$seg.mean >= 0.5等于df1$id == gain和df1$seg.mean <= -0.5等于df1$id == loss ，在 df1$Occurance 中插入 1 。 对于那些不满足此条件的行，分配 df1$Occurance == 0

df1 <-
    Chr start       end     num.mark    seg.mean    id
    1   68580000    68640000    8430    0.7       gain
    1   115900000   116260000   8430    0.0039    loss
    1   173500000   173680000   5      -1.7738    loss
    1   173500000   173680000   12       0.011    loss
    1   173840000   174010000   6      -1.6121    loss

期望的输出

Chr     start       end     num.mark    seg.mean  id    Occurance
    1   68580000    68640000    8430    0.7       gain      1
    1   115900000   116260000   8430    0.0039    loss      0
    1   173500000   173680000   5      -1.7738    loss      1
    1   173500000   173680000   12       0.011    loss      0
    1   173840000   174010000   6      -1.6121    loss      1

Answer 1

尝试使用ifelse

df1$Occurance <- ifelse((df1$seg.mean >= 0.5 & df1$id == "gain") | 
                      (df1$seg.mean <= -0.5 & df1$id == "loss"), 1, 0)

编辑:避免 ifelse 并使用 within ，这样就不必一直编写 df1

transform(df1, Occurance = as.numeric((seg.mean >= 0.5 & id == "gain") |
                                        (seg.mean <= -0.5 & id == "loss")))

评论:如果您也接受 TRUE/FALSE 代替 1/0，您可以跳过 as.numeric

编辑#2:如果您想要多个结果，例如 -1,0,1，您可以执行以下操作

df1$Occurance = 0
within(df1, {Occurance[seg.mean >= 0.5 & id == "gain"] <- 1;
             Occurance[seg.mean <= -0.5 & id == "loss"] <- -1})

结果

  Chr     start       end num.mark seg.mean   id Occurance
1   1  68580000  68640000     8430   0.7000 gain         1
2   1 115900000 116260000     8430   0.0039 loss         0
3   1 173500000 173680000        5  -1.7738 loss        -1
4   1 173500000 173680000       12   0.0110 loss         0
5   1 173840000 174010000        6  -1.6121 loss        -1