Question

如何根据数据框中任何位置可能出现的特定值过滤数据集，而不一定在任何一列或一行下？

假设我有一个类似这样的数据框。

   id gender group Student_Math_1 Student_Math_2 Student_Read_1 Student_Read_2
   46      M   Red             23             45             37             56
   46      M   Red             34             36             33             78
   46      M   Red             56             63             58             NA
   62      F  Blue             59             NA             NA             68
   62      F  Blue             NA             68             87             73
   38      M   Red             78             57             NA             65
   38      M   Red             NA             75             54             NA
   17      F  Blue             74             NA             56             72
   17      F  Blue             75             61             NA             79
   17      F  Blue             NA             74             43             81

我正在尝试对此数据框进行子集，以便保留包含值68的所有行和列，而不管它在数据框中的位置。

最终输出为

   id gender group Student_Math_1 Student_Math_2 Student_Read_1 Student_Read_2

   62      F  Blue             59             NA             NA             68
   62      F  Blue             NA             68             87             73

欢迎任何提示或建议。提前谢谢。

df = structure(list(id = c(46, 46, 46, 62, 62, 38, 38, 17, 17, 17), 
    gender = structure(c(2L, 2L, 2L, 1L, 1L, 2L, 2L, 1L, 1L, 
    1L), .Label = c("F", "M"), class = "factor"), group = structure(c(2L, 
    2L, 2L, 1L, 1L, 2L, 2L, 1L, 1L, 1L), .Label = c("Blue", "Red"
    ), class = "factor"), Student_Math_1 = c(23, 34, 56, 59, 
    NA, 78, NA, 74, 75, NA), Student_Math_2 = c(45, 36, 63, NA, 
    68, 57, 75, NA, 61, 74), Student_Read_1 = c(37, 33, 58, NA, 
    87, NA, 54, 56, NA, 43), Student_Read_2 = c(56, 78, NA, 68, 
    73, 65, NA, 72, 79, 81)), .Names = c("id", "gender", "group", 
"Student_Math_1", "Student_Math_2", "Student_Read_1", "Student_Read_2"
), row.names = c(NA, -10L), class = "data.frame")

Answer 1

怎么样：

## use data from "Student_Math_1" column to "Student_Read_2" column
df[rowSums(df[4:7] == 68, na.rm = TRUE) > 0, ]

#  id gender group Student_Math_1 Student_Math_2 Student_Read_1 Student_Read_2
#4 62      F  Blue             59             NA             NA             68
#5 62      F  Blue             NA             68             87             73

注意，df[4:7] == 68会返回一个逻辑矩阵（NA}），我们会将rowSums与na.rm = TRUE一起使用。在此类算术运算期间，TRUE看到1，FALSE看到0。

<强>后续

感谢Ben Bolker提醒这个更具可读性的解决方案，如果你正在学习R，你当然需要掌握它：

df[apply(df[4:7] == 68, 1L, any, na.rm = TRUE), ]

适用于行any（带na.rm = TRUE）。我不记得我在哪里比较这两个表现。但我不打算做一个快速的实验：

library(microbenchmark)

## For simplicity / neatness, I generate a logical matrix `X` without `NA`
X <- matrix(sample(c(TRUE, FALSE), 2000 * 10, replace = TRUE), 2000)

## also measuring 989's solution
microbenchmark(ZL = rowSums(X) > 0,
               Ben = apply(X, 1L, any),
               "989" = unique(which(X, arr.ind = T)[,1]))

#Unit: microseconds
# expr     min      lq      mean  median      uq     max neval cld
#   ZL  144.24  149.76  183.3516  164.86  172.48 2077.80   100 a  
#  Ben 5610.08 5730.78 6003.0660 5779.20 5861.46 8021.72   100   c
#  989 1571.72 1639.58 2033.4224 1664.78 1721.18 5339.48   100  b

Answer 2

可替换地，

unique

在这种情况下，您无需关心列的位置或return array('doctrine' => array( 'connection' => array('orm_default' => 'config', 'authentication' => array( // this part is for the Auth adapter from DoctrineModule/Authentication 'orm_default' => array( 'object_manager' => 'Doctrine\ORM\EntityManager', // object_repository can be used instead of the object_manager key 'identity_class' => 'Easysurvey\Entity\User', //'Application\Entity\User', 'identity_property' => 'username', // 'username', // 'email', 'credential_property' => 'password', // 'password', 'credential_callable' => function(Entity\User $user, $passwordGiven) { if ($user->getPassword() == Pbkdf2::calc('sha256', $passwordGiven, $user->getSalt(), 10000, 32)) { return true; } else { return false; } }, ), ),出现的位置。如果案例68每行出现多次，则使用$("#button").click(function() { $("#square").addClass("animate").delay(400).queue(function(next) { $(this).removeClass("animate"); next(); }); });。

按条目过滤数据框

2 个答案: