r - 插入符号错误 : "all the Accuracy metric values are missing"

Question

我收到以下错误，我不知道可能出了什么问题。
我将 R Studio 与适用于 Windows 8.1 的 3.1.3 版 R 一起使用，并使用 Caret 包进行数据挖掘。

我有以下训练数据:
str(training)

'data.frame':   212300 obs. of  21 variables:

 $ FL_DATE_MDD_MMDD     : int  101 101 101 101 101 101 101 101 101 101 ...

 $ FL_DATE              : int  1012013 1012013 1012013 1012013 1012013 1012013 1012013 1012013 1012013 1012013 ...

 $ UNIQUE_CARRIER       : Factor w/ 13 levels "9E","AA","AS",..: 11 10 2 5 8 9 11 10 10 10 ...

 $ DEST                 : Factor w/ 150 levels "ABE","ABQ","ALB",..: 111 70 82 8 8 31 110 44 53 80 ...

 $ DEST_CITY_NAME       : Factor w/ 148 levels "Akron, OH","Albany, NY",..: 107 61 96 9 9 29 106 36 97 78 ...

 $ ROUNDED_TIME         : int  451 451 551 551 551 551 551 551 551 551 ...

 $ CRS_DEP_TIME         : int  500 520 600 600 600 600 600 600 602 607 ...

 $ DEP_DEL15            : Factor w/ 2 levels "0","1": 1 2 1 1 1 1 1 2 1 1 ...

 $ CRS_ARR_TIME         : int  746 813 905 903 855 815 901 744 901 841 ...

 $ Conditions           : Factor w/ 28 levels "Blowing Snow",..: 2 2 2 2 2 2 2 2 2 2 ...

 $ Dew.PointC           : num  -14.4 -14.4 -14.4 -14.4 -14.4 -14.4 -14.4 -14.4 -14.4 -14.4 ...

 $ Events               : Factor w/ 10 levels "","Fog","Fog-Rain",..: 1 1 1 1 1 1 1 1 1 1 ...

 $ Gust.SpeedKm.h       : num  NA NA NA NA NA NA NA NA NA NA ...

 $ Humidity             : int  68 68 71 71 71 71 71 71 71 71 ...

 $ Precipitationmm      : num  NA NA NA NA NA NA NA NA NA NA ...

 $ Sea.Level.PressurehPa: num  1021 1021 1022 1022 1022 ...

 $ TemperatureC         : num  -9.4 -9.4 -10 -10 -10 -10 -10 -10 -10 -10 ...

 $ VisibilityKm         : num  16.1 16.1 16.1 16.1 16.1 16.1 16.1 16.1 16.1 16.1 ...

 $ Wind.Direction       : Factor w/ 18 levels "Calm","East",..: 9 9 7 7 7 7 7 7 7 7 ...

 $ WindDirDegrees       : int  320 320 330 330 330 330 330 330 330 330 ...

 $ Wind.SpeedKm.h       : num  20.4 20.4 13 13 13 13 13 13 13 13 ...

 - attr(*, "na.action")=Class 'omit'  Named int [1:22539] 3 32 45 87 94 325 472 548 949 1333 ...

  .. ..- attr(*, "names")= chr [1:22539] "3" "32" "45" "87" ...

当我执行以下命令时:

ldaModel <- train(DEP_DEL15~.,data=training,method="lda",preProc=c("center","scale"),na.remove=TRUE)

我得到:

Something is wrong; all the Accuracy metric values are missing: Accuracy Kappa
Min. : NA Min. : NA
1st Qu.: NA 1st Qu.: NA
Median : NA Median : NA
Mean :NaN Mean :NaN
3rd Qu.: NA 3rd Qu.: NA
Max. : NA Max. : NA
NA's :1 NA's :1
Error in train.default(x, y, weights = w, ...) : Stopping

Answer 1

这可能是由于具有“0”和“1”级别的结果因子。

发生这种情况时会发出特定警告:At least one of the class levels are not valid R variables names; This may cause errors if class probabilities are generated because the variables names will be converted to: X0, X1"
似乎人们一致忽略警告，所以我打算在下一个版本中抛出一个错误。