引用类似乎只接受允许的基本/标准对象类型。例如,我想要一个chron对象,但这不允许我定义它:
> newclass <- setRefClass("newclass",fields=list(time="chron"))
Error in refClassInformation(Class, contains, fields, methods, where) :
class "chron" for field 'time' is not defined
这是限制还是有更好的方法?我尝试过在initialize
方法中设置它,但显然这不是一种方法:
> newclass <- setRefClass("newclass",
+ fields=list(time="numeric"),
+ methods=list(initialize=function() time <<- as.chron(time)))
library(chron)
> x <- newclass(time=as.chron("2011-01-01"))
Error in .Object$initialize(...) : unused argument (time = 14975)
答案 0 :(得分:8)
我认为您需要先使用setOldclass
注册非标准课程。
require(chron)
dts <- dates(c("05/20/13", "06/10/13"))
tms <- times(c("19:30:00", "22:30:05"))
setOldClass("chron")
newclass <- setRefClass("newclass",
fields = list(time = "chron"))
mydate <- newclass(time = chron(dates = dts, times = tms))
mydate$time
## [1] (05/20/13 19:30:00) (06/10/13 22:30:05)