R：遍历列，从列中选择值并将其写入同一行中的新列

我有以下格式的数据帧

id   var1  val1 status1 var2 val2 status2 var3 val3 status3 
123  a     12   false   b    23   true    c    34   true    

在这里，我想遍历每一行的每一列，获取变量的第一个status true，并将其保存到新行。下面是上述示例的预期输出

有没有一种方法可以在不使用2 for循环的情况下执行此操作。（循环中的循环）

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在我看来，处理长格式的数据会更容易。因此，首先是从宽到长进行重塑

dat_long <- reshape(dat, idvar = "id", varying = 2:ncol(dat), direction = "long", sep = "")

结果

dat_long
#       id time var val status firstOccured
#123.1 123    1   a  12  false            b
#123.2 123    2   b  23   true            b
#123.3 123    3   c  34   true            b

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如果我们需要回到广域格式，我们可以这样做

out <- reshape(dat_long, idvar = "id", timevar = "time", direction = "wide", sep = "")
out <- out[setdiff(names(out), c("firstOccured1", "firstOccured2"))]
out
#       id var1 val1 status1 var2 val2 status2 var3 val3 status3 firstOccured3
#123.1 123    a   12   false    b   23    true    c   34    true             b

out
dat_long
#       id time var val status firstOccured
#123.1 123    1   a  12  false            b
#123.2 123    2   b  23   true            b
#123.3 123    3   c  34   true            b

out <- reshape(dat_long, idvar = "id", timevar = "time", direction = "wide", sep = "")
out <- out[setdiff(names(out), c("firstOccured1", "firstOccured2"))]
out
#       id var1 val1 status1 var2 val2 status2 var3 val3 status3 firstOccured3
#123.1 123    a   12   false    b   23    true    c   34    true             b

dat <- structure(list(id = 123L, var1 = "a", val1 = 12L, status1 = "false", 
    var2 = "b", val2 = 23L, status2 = "true", var3 = "c", val3 = 34L, 
    status3 = "true"), .Names = c("id", "var1", "val1", "status1", 
"var2", "val2", "status2", "var3", "val3", "status3"), class = "data.frame", row.names = c(NA, 
-1L))