r - 如何在数据框中的一行中找到第一个 NA 实例？

Question

我如何才能看到第一个 NA 出现在数据框中的哪一行(在哪一列中)？

我正在研究参与者在 10 步长的过程中退出的点。

每个步骤都通过相应的列进行标识，这意味着总共有 10 列。

我可以判断某人是否已完成任何一个步骤的方法是我是否在列中看到日期时间值，该值指示他们完成该步骤的时间。

如果他们尚未完成该步骤，它将显示 NA，以下列也将显示。

例如，如果我在特定行的第 5 列中看到 NA ，那么我知道该特定用户没有继续执行第 4 步，因为其余列也将显示 NA 。

这个想法是参与者完成所有 10 个步骤，这意味着他们已经完整地完成了整个过程。

我希望能够确定最常见的下车点。

我的数据集有 2,000 行深 - 我如何快速检查和/或识别它？

样本数据:

structure(list(associate = c("tXQCMHwGFy", "JzObuwUnkJ", "2fM04XFVja", 
"uFsZTj2i2M", "ZsI0u5ka2j", "9r98DMXxFE", "NtmXw4qnIa", "oGB0Ugi93h", 
"G0r2yOxM7s", "MIpQqbBagS", "HCGJ5kSOlk", "3ljP9FuGcA", "5k7OvbBZUH", 
"6DDEbTWhBD", "xuU5Ewninw", "5UGABh3kcg", "G5etNVDoEH", "ejlCBv3dp2", 
"2DUWxEFt6o", "sCJeaxCSk5", "sb9QKBDSHl", "E8n3XZSS1x", "Ld7rFWFKag", 
"ykziBo9kOx", "Z9mOsGpDNE"), accountCreation = structure(c(1524606379.904, 
1528147858.812, 1521994536.637, 1522097826.043, 1528150007.134, 
1526575446.645, 1523493362.438, 1528123246.558, 1528135004.808, 
1527791947.924, 1526755863.609, 1525455650.394, 1523409400.766, 
1524347073.427, 1526134766.407, 1523638698.97, 1527878066.61, 
1524855389.236, 1526309009.378, 1520972884.396, 1527180696.03, 
1527268883.689, 1521646455.016, 1526837992.595, 1521040859.622
), class = c("POSIXct", "POSIXt")), profileSetup = structure(c(1524606693.345, 
1528148032.015, 1521994616.897, 1522097826.043, 1528186485.637, 
1526575497.987, 1523493556.798, 1528123314.197, 1528135180.95, 
1527792152.877, 1526756131.911, 1525455787.847, 1523409400.766, 
1524347073.427, 1526134850.566, 1523638905.289, 1527878482.462, 
1524855535.686, 1526309106.294, 1522186725.043, 1527180799.909, 
1527269009.143, 1521646455.016, 1526838102.323, 1521040859.622
), class = c("POSIXct", "POSIXt")), profilesetupDuration = c(314, 
174, 80, 0, 36478, 51, 194, 68, 176, 205, 268, 137, 0, 0, 84, 
207, 416, 146, 97, 1213841, 103, 126, 0, 110, 0), introductionSplash = structure(c(1524872052.263, 
1528148043.062, 1521995730.924, 1522097826.043, 1528186496.499, 
1526575506.96, 1523493567.959, 1528123329.044, 1528135237.755, 
1527792185.349, NA, 1525455815.855, 1523409400.766, 1524347073.427, 
1526134861.747, 1523638967.684, 1527878727.235, 1524855546.038, 
1526309117.104, 1522186739.397, NA, 1527269018.641, 1521646455.016, 
1526838112.374, 1521040859.622), class = c("POSIXct", "POSIXt"
)), introductionSplashDuration = c(265673, 185, 1194, 0, 36489, 
60, 205, 83, 233, 238, NA, 165, 0, 0, 95, 269, 661, 157, 108, 
1213855, NA, 135, 0, 120, 0), introduction = structure(c(1525124180.491, 
1528148744.594, 1521996568.337, 1522097826.043, NA, 1526576050.815, 
1523495507, 1528126805.572, NA, 1527792470.951, NA, 1525456759.777, 
1523409400.766, 1524347073.427, 1526135265.531, 1523639316.761, 
1527878956.368, 1524861227.537, 1526310376.89, 1522187755.31, 
NA, 1527269672.153, 1521646455.016, 1526838283.459, 1521040859.622
), class = c("POSIXct", "POSIXt")), introductionDuration = c(517801, 
886, 2032, 0, NA, 604, 2145, 3559, NA, 523, NA, 1109, 0, 0, 499, 
618, 890, 5838, 1367, 1214871, NA, 789, 0, 291, 0), demoChatSkipped = structure(c(NA, 
1528148761.447, NA, 1522097826.043, NA, 1526576060.249, NA, NA, 
NA, 1527792487.742, NA, 1525456803.893, 1523409400.766, 1524347073.427, 
1526147587.803, NA, NA, NA, NA, NA, NA, 1527269694.132, 1521646455.016, 
1526838287.934, 1521040859.622), class = c("POSIXct", "POSIXt"
)), demoChatSkippedDuration = c(NA, 903, NA, 0, NA, 614, NA, 
NA, NA, 540, NA, 1153, 0, 0, 12821, NA, NA, NA, NA, NA, NA, 811, 
0, 295, 0), approval = structure(c(1525124264.718, 1528148756.313, 
1522018833.517, 1522097826.043, NA, 1526576055.489, 1523538955.529, 
1528136805.681, NA, 1527792479.256, NA, 1525456805.673, 1523409400.766, 
1524347073.427, 1526147585.05, 1523639448.648, 1527879134.158, 
1524861732.505, 1526315087.819, 1522188033.261, 1527180827.746, 
1527269692.115, 1521646455.016, 1526838288.734, 1521040859.622
), class = c("POSIXct", "POSIXt")), approvalDuration = c(517885, 
898, 24297, 0, NA, 609, 45593, 13559, NA, 532, NA, 1155, 0, 0, 
12819, 750, 1068, 6343, 6078, 1215149, 131, 809, 0, 296, 0), 
    tutorial = structure(c(NA, NA, NA, 1522097826.043, NA, NA, 
    NA, NA, NA, NA, NA, NA, 1523409400.766, 1524347073.427, NA, 
    NA, NA, NA, NA, NA, NA, NA, 1521646455.016, NA, 1521040859.622
    ), class = c("POSIXct", "POSIXt")), tutorialDuration = c(NA, 
    NA, NA, 0, NA, NA, NA, NA, NA, NA, NA, NA, 0, 0, NA, NA, 
    NA, NA, NA, NA, NA, NA, 0, NA, 0), letsbegin = structure(c(1525124456.616, 
    1528148773.37, 1522031049.317, 1522097826.043, NA, 1526576071.6, 
    1523538956.159, 1528136822.297, NA, 1527794019.564, NA, 1525456849.582, 
    1523409400.766, 1524347073.427, 1526312517.824, 1523639449.148, 
    1527879134.675, 1524861750.153, 1526317200.235, 1522188066.352, 
    1527180828.158, NA, 1521646455.016, 1527015876.057, 1521040859.622
    ), class = c("POSIXct", "POSIXt")), letsbeginDuration = c(518077, 
    915, 36513, 0, NA, 625, 45594, 13576, NA, 2072, NA, 1199, 
    0, 0, 177751, 751, 1068, 6361, 8191, 1215182, 132, NA, 0, 
    177884, 0), demoChatDuration = c(517884, NA, 24297, NA, NA, 
    NA, 2499, 13559, NA, NA, NA, NA, NA, NA, 13201, 729, 1029, 
    6342, 6078, 1215148, NA, 967, NA, NA, NA)), row.names = c(937L, 
1941L, 396L, 30L, 1950L, 1337L, 602L, 1812L, 1872L, 1719L, 1423L, 
1077L, 173L, 234L, 1204L, 680L, 1748L, 989L, 1243L, 251L, 1568L, 
1615L, 196L, 1451L, 154L), class = "data.frame")

Answer 1

如果您想将列的名称添加到 data.frame 中，则可以执行以下操作:

创建一些数据，mtcars 的前 10 条记录。用 NA 复制你的情况到最后。

df <- mtcars[1:10, ]
df[3, 3:11] <- NA
df[6, 5:11] <- NA

df$dropofpoint <- apply(df, 1, function(x) names(which(is.na(x)))[1])

head(df)
                   mpg cyl disp  hp drat    wt  qsec vs am gear carb dropofpoint
Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4        <NA>
Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4        <NA>
Datsun 710        22.8   4   NA  NA   NA    NA    NA NA NA   NA   NA        disp
Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1        <NA>
Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2        <NA>
Valiant           18.1   6  225 105   NA    NA    NA NA NA   NA   NA        drat