如何在 R 中使用类似命名的方法创建多个 S4 类？

问题描述

我正在尝试使用两个 S4 类 Myclass 和 Mynewclass 构建一个 R 包，它们具有类似命名的方法 parameters 和 parameters<-

#' Example docstring of Myclass
#'
#' @slot parameters_names names of the parameters which are used by the
#'     model.
#' @slot parameters parameters which are used by the
#'     model.
#'
#' @import tidyverse
#' @import reshape2
#' @importFrom methods new
#' @export Myclass
#' 
Myclass <- setClass('Myclass',# slots
                    slots = c(
                      parameters_names = 'list',parameters = 'list'
                    ),# prototypes for the slots,automatically set output and param
                    # names
                    prototype = list(
                      parameters_names = list('a','b'),parameters = vector(mode = "list",length = 2)
                    )
)

# Setter and getter methods for parameters

#' Retrieves parameters Myclass.
#'
#' @param object An object of the class Myclass.
#'
#' @return parameter values of Myclass.
#' @rdname Myclass-class
#' @export
setGeneric('parameters',function(object) standardGeneric('parameters'))

#' @describeIn Myclass Retrieves parameters Myclass.
#'
#' @param object An object of the class Myclass.
#'
#' @return parameter values of Myclass.
#' @aliases parameters,ANY,ANY-method
#' @rdname Myclass-class
#' @export
setMethod('parameters','Myclass',function(object) object@parameters)

#' Sets parameters of Myclass,#' 
#' @param object An object of the class Myclass
#' @param value a named list of (a,b).
#'
#' @return Updated version of Myclass.
#' @rdname Myclass-class
#' @export
setGeneric(
  'parameters<-',function(object,value){
    standardGeneric('parameters<-')
  })

#' @describeIn Myclass Sets parameters of Myclass.
#'
#' @param object An object of the class Myclass.
#' @param value a named list of (a,b).
#'
#' @return Updated version of Myclass.
#' @aliases parameters<-,ANY-method
#' @rdname Myclass-class
#' @export
setMethod(
  'parameters<-',value) {
    a = value$a
    b = value$b
    ic <- list(a,b)
    # if all above tests are passed,assign the ic namelist to the object
    object@parameters <- ic
    
    return(object)
  })

和

#' Example docstring of Mynewclass
#'
#' @slot parameters_names names of the parameters which are used by the
#'     model.
#' @slot parameters parameters which are used by the
#'     model.
#'
#' @import tidyverse
#' @import reshape2
#' @importFrom methods new
#' @export Mynewclass
#' 
Mynewclass <- setClass('Mynewclass','b','c'),length = 3)
                    )
)

# Setter and getter methods for parameters

#' Retrieves parameters Mynewclass.
#'
#' @param object An object of the class Mynewclass.
#'
#' @return parameter values of Mynewclass.
#' @rdname Mynewclass-class
#' @export
setGeneric('parameters',function(object) standardGeneric('parameters'))

#' @describeIn Mynewclass Retrieves parameters Mynewclass.
#'
#' @param object An object of the class Mynewclass.
#'
#' @return parameter values of Mynewclass.
#' @aliases parameters,ANY-method
#' @rdname Mynewclass-class
#' @export
setMethod('parameters','Mynewclass',function(object) object@parameters)

#' Sets parameters of Mynewclass,#' 
#' @param object An object of the class Mynewclass
#' @param value a named list of (a,b,c).
#'
#' @return Updated version of Mynewclass.
#' @rdname Mynewclass-class
#' @export
setGeneric(
  'parameters<-',value){
    standardGeneric('parameters<-')
  })

#' @describeIn Mynewclass Sets parameters of Mynewclass.
#'
#' @param object An object of the class Mynewclass.
#' @param value a named list of (a,c).
#'
#' @return Updated version of Mynewclass.
#' @aliases parameters<-,ANY-method
#' @rdname Mynewclass-class
#' @export
setMethod(
  'parameters<-',value) {
    a = value$a
    b = value$b
    c = value$c
    ic <- list(a,c)
    # if all above tests are passed,assign the ic namelist to the object
    object@parameters <- ic
    
    return(object)
  })

但是，每当我尝试使用 devtools::document() 时，都会出现以下错误消息

Error in methods::getMethod(name,eval(call$signature),where = env) : no method found for function 'parameters' and signature Myclass

如何在不为方法指定不同名称的情况下解决此问题？

解决方法

尽量不要在两个文件中都调用 setGeneric。

对 Mynewclass 的重复调用可能会创建一个新的泛型，并删除前一个泛型（包括其关联方法）。这为您留下了一个仅用于 {{1}} 的方法。

另见 https://stat.ethz.ch/pipermail/r-devel/2010-January/056396.html