Question

在对data.table进行剪切时遇到以下问题。我不知道为什么它没有通过“prod”正确地进行过滤。如果我在外面运行切割，如下所示，它会正确切割但不在数据表中。你知道我为什么以及如何修理它？谢谢

library(data.table)
    db<-data.frame(count=c(331948, 334999, 321000, 305000, 324100, 310000, 305000, 325000, 305000, 329999, 315000,531948, 534999, 521000, 505000, 524100, 510000, 505000, 525000, 505000, 529999, 515000), prod=c("a","a","a","a","a","a","a","a","a","a","a","b","b","b","b","b","b","b","b","b","b","b"))

head(db)

    count prod
1  331948    a
2  334999    a
3  321000    a
4  305000    a
5  324100    a
6  310000    a

setDT(db)[ , id := cut(count,8,digits=1,dig.lab = 7), by = prod]

    count prod                  id
1: 331948    a   (531249.1,535029]
2: 334999    a   (531249.1,535029]
3: 321000    a (519999.5,523749.4]
4: 305000    a   (504970,508749.9]
5: 324100    a (523749.4,527499.2]
6: 310000    a (508749.9,512499.8]

table(db[db$prod=='a',]$id)

 (504970,508749.9] (508749.9,512499.8] (512499.8,516249.6] (516249.6,519999.5] (519999.5,523749.4] (523749.4,527499.2] (527499.2,531249.1]   (531249.1,535029] 
                  3                   1                   1                   0                   1                   2                   1                   2 

table(cut(db[db$prod=='a',]$count,8,digits=1,dig.lab = 7))

(304970,308749.9] (308749.9,312499.8] (312499.8,316249.6] (316249.6,319999.5] (319999.5,323749.4] (323749.4,327499.2] (327499.2,331249.1]   (331249.1,335029] 
                  3                   1                   1                   0                   1                   2                   1                   2

Answer 1

您可以尝试首先将var jsonObject = "[{" for i in 1...table.count { var str = "" var insideStr = String() for property in properties { let filteredTable = table.value(forKey: property) as! [Any] insideStr += "\"\(property)\": \"\(filteredTable[i - 2])\"," } let index = insideStr.characters.index(insideStr.startIndex, offsetBy: (insideStr.count - 2)) insideStr = String(insideStr[...index]) str += "\(insideStr)}]," jsonObject.append(str) } let index = jsonObject.characters.index(jsonObject.startIndex, offsetBy: (jsonObject.count - 2)) jsonObject = "\(String(jsonObject[...index]))" return jsonObject }catch let error { print("\(error)") }的分组输出转换为cut并添加一列。现在在下一个语句中将新列（包含字符）转换为character而不对任何内容进行分组。通过这种方式，您将能够避免分组因素强制转换为相同的值。

您可以尝试：

factor

R CUT数据表

1 个答案: