Question

我有一个包含许多列的数据集，我必须选择它们的一部分并重命名它们以便偶尔进行分析。我现在使用包select中的dplyr。但是，每次为许多属性进行设置都很复杂。有没有更好的方法来做到这一点？

例如，我使用数据集mtcars

> head(mtcars)
                   mpg cyl disp  hp drat    wt  qsec vs am gear carb
Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

我想选择列：mpg，cyl，并将其重命名为x，y

我现在使用：

> df <- mtcars %>% select(x=mpg, y=cyl)
> head(df)
                     x y
Mazda RX4         21.0 6
Mazda RX4 Wag     21.0 6
Datsun 710        22.8 4
Hornet 4 Drive    21.4 6
Hornet Sportabout 18.7 8
Valiant           18.1 6

它有效，但是当我经常更改括号中的参数时，这很麻烦。我希望使用列表来解决问题，但它不起作用。

例如，我希望创建一个属性列表以简化：

myselection <- c(
  x = mpg,
  y = cyl
)

df <- mtcars %>% select(myselection) # It is wrong!

但这是错误的，我怎样才能让它发挥作用？

Answer 1

您需要非标准的评估（技术上，这是标准评估，正常的dplyr使用是NSE），请参阅vignette("nse")：

library(dplyr)

dots <- list(x="mpg", y="cyl")
select_(mtcars, .dots = dots)

Answer 2

基础R替代可能是

Sub selectFile()

Dim wbI As Workbook, wbO As Workbook
Dim wsI As Worksheet

Set wbI = ThisWorkbook
'sheet where you want to import the sheet in
Set wsI = wbI.Sheets("Sheet_Items")

ChDir (Environ("USERPROFILE") & "\Desktop")
 'Select the file
Fname = Application.GetOpenFilename(filefilter:="Text Files (*.txt),*.txt", MultiSelect:=False)

' check if file is selected
If Fname = False Then
'    MsgBox "No File Was Selected"
    Exit Sub
End If

' delete the current content there
Sheets("Sheet_Items").Range("G3:AB50000").ClearContents

'Set wbO = Workbooks.Open(Fname)
'
'wbO.Sheets(1).Cells.Copy wsI.Cells
'
'wbO.Close SaveChanges:=False
Dim var As String

var = "TEXT;" & Fname
With ActiveSheet.QueryTables.Add(Connection:= _
        var, Destination:=Range("$G$3") _
        )
        .Name = "Sample"
        .FieldNames = True
        .RowNumbers = False
        .FillAdjacentFormulas = False
        .PreserveFormatting = True
        .RefreshOnFileOpen = False
        .RefreshStyle = xlInsertDeleteCells
        .SavePassword = False
        .SaveData = True
        .AdjustColumnWidth = True
        .RefreshPeriod = 0
        .TextFilePromptOnRefresh = False
        .TextFilePlatform = 437
        .TextFileStartRow = 1
        .TextFileParseType = xlDelimited
        .TextFileTextQualifier = xlTextQualifierDoubleQuote
        .TextFileConsecutiveDelimiter = False
        .TextFileTabDelimiter = True
        .TextFileSemicolonDelimiter = True
        .TextFileCommaDelimiter = False
        .TextFileSpaceDelimiter = False
        .TextFileColumnDataTypes = Array(1, 1, 1, 1, 1, 1)
        .TextFileTrailingMinusNumbers = True
        .Refresh BackgroundQuery:=False
    End With



'You need to properly qualify the range for the Replace() method
Columns("S").Replace What:=".", _
                            Replacement:=",", _
                            LookAt:=xlPart, _
                            SearchOrder:=xlByRows, _
                            MatchCase:=False, _
                            SearchFormat:=False, _
                            ReplaceFormat:=False

Columns("T").Replace What:=".", _
                            Replacement:=",", _
                            LookAt:=xlPart, _
                            SearchOrder:=xlByRows, _
                            MatchCase:=False, _
                            SearchFormat:=False, _
                            ReplaceFormat:=False

'Range("S3:S100000") = Range("S3:S100000").Value
'Range("T3:T100000") = Range("T3:T100000").Value
'
'convert to number
'for further details on other available formats have a look at: http://stackoverflow.com/questions/20648149/what-are-numberformat-options-in-excel-vba
'Range("S:S").NumberFormat = "0"
'Range("T:T").NumberFormat = "0"

''get an emtpy cell
'Sheets("Sheet_Items").Range("ZZ100000").Copy
'Sheets("Sheet_Items").Range("S3:S100000").PasteSpecial , xlPasteSpecialOperationAdd
'
'Sheets("Sheet_Items").Range("ZZ100000").Copy
'Sheets("Sheet_Items").Range("T3:T100000").PasteSpecial , xlPasteSpecialOperationAdd

'select the cell B1
Sheets("Sheet_Items").Range("B1").Select

End Sub

如何从R中的数据框中选择和重命名列的长列？

2 个答案: