RxLinMod() 是否有运行"按"组的几个回归的能力？
rxLinMod() 不直接具有这种能力。若要执行此操作的一种方法是使用 rxSplit() 函数创建单独 XDF 的文件，另一个用于每个唯一的组值，然后在调用 rxLinMod() 来计算每个拆分 XDF 文件不同衰退的循环中。
例如，使用大航空公司的数据，从这里http://packages.revolutionanalytics.com/datasets/下载
创建 7 不同 XDF 的文件，一周中的每一天。然后计算线性回归模型，在周中的每一天。
rxGetVarInfo( "C:/MyRData/AirlineData87to08.xdf") Var 1: Year
22 factor levels: 1987 1988 1989 1990 1991 ... 2004 2005 2006 2007 2008
Var 2: Month
12 factor levels: January February March April May ... August September October November December
Var 3: DayofMonth
31 factor levels: 1 2 3 4 5 ... 27 28 29 30 31
Var 4: DayOfWeek
7 factor levels: Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Var 5: DepTime, Type: integer, Low/High: (0, 29)
Var 6: CRSDepTime, Type: integer, Low/High: (0, 24)
Var 7: ArrTime, Type: integer, Low/High: (0, 29)
Var 8: CRSArrTime, Type: integer, Low/High: (0, 24)
Var 9: UniqueCarrier
29 factor levels: PS TW UA WN EA ... HA OH F9 YV 9E
Var 10: FlightNum
8160 factor levels: 1451 1453 1454 1455 1457 ... 9742 9743 6813 6913 6513
Var 11: TailNum
13537 factor levels: NA N7298U N7449U N7453U N7288U ... N516AS N763JB N766JB N75428 N75429
Var 12: ActualElapsedTime, Type: integer, Low/High: (-719, 1883)
Var 13: CRSElapsedTime, Type: integer, Low/High: (-1240, 1613)
Var 14: AirTime, Type: integer, Low/High: (-3818, 3508)
Var 15: ArrDelay, Type: integer, Low/High: (-1437, 2598)
Var 16: DepDelay, Type: integer, Low/High: (-1410, 2601)
Var 17: Origin
347 factor levels: SAN SFO BUR OAK LAX ... ROW GCC RKS MKG OTH
Var 18: Dest
352 factor levels: SFO RNO OAK BUR LAX ... PIR GCC RKS MKG OTH
Var 19: Distance, Type: integer, Low/High: (0, 4983)
Var 20: TaxiIn, Type: integer, Low/High: (0, 1523)
Var 21: TaxiOut, Type: integer, Low/High: (0, 3905)
Var 22: Cancelled, Type: logical, Low/High: (0, 1)
Var 23: CancellationCode
4 factor levels: A B C D
Var 24: Diverted, Type: logical, Low/High: (0, 1)
Var 25: CarrierDelay, Type: integer, Low/High: (0, 2580)
Var 26: WeatherDelay, Type: integer, Low/High: (0, 1510)
Var 27: NASDelay, Type: integer, Low/High: (-60, 1392)
Var 28: SecDelay, Type: integer, Low/High: (0, 533)
Var 29: LateAircraftDelay, Type: integer, Low/High: (0, 1407)
Var 30: Late, Type: logical, Low/High: (0, 1)
Var 31: LateNew
2 factor levels: 1 0
rxSplit(inData = "C:/MyRData/AirlineData87to08.xdf", splitByFactor = "DayOfWeek", outFilesBase = "")
lmresults <- vector("list", length = 0L)
for (i in 1:length(myinfo$DayOfWeek)[[5]]
{
dataFile = paste("C:/MyRData/AirlineData87to08-ByDay.DayOfWeek.",myfac[i],".xdf", sep = "")
lmresults[[i]] <- rxLinMod(ArrDelay ~ CRSDepTime, data = dataFile)
assign("lmresults", lmresults, pos = 1)
}
