R: General S4 Class Extractor Functions

getS4 {fBasics} | R Documentation

## General S4 Class Extractor Functions

### Description

A collection and description of functions to extract slots from S4 class objects.

The extractor functions are:

`getModel` | Extracts the model slot from a S4 object,
`getTitle` | Extracts the title slot from a S4 object,
`getDescription` | Extracts the description slot from a S4 object,
`getSlot` | Extracts a specified slot from a S4 object,
`getArgs` | Shows the arguments of a S4 function.

Since R version 2.14.0, a generic `getCall()` is part of R; for earlier versions, we had provided a simple version for S4 objects.

### Usage

    getModel(object)
    getTitle(object)
    getDescription(object)

    getSlot(object, slotName)

    getArgs(f, signature)

### Arguments

`f` | a generic function or the character-string name of one.
`object` | an object of class S4.
`signature` | the signature of classes to match to the arguments of `f`
`slotName` | a character string, the name of the slot to be extracted from the S4 object.
`...` | Further arguments to be passed to function.

### Value

`getModel`
`getTitle`
`getDescription`
`getSlot`
return the content of the slot.

`getArgs` returns the names of the arguments.

### Examples

    ## Example S4 Representation:
       # Hyothesis Testing with Control Settings
       setClass("hypTest",
         representation(
           call = "call",
           data = "numeric",
           test = "list",
           description = "character")
       )

    ## Shapiro Wilk Normaility Test
       swTest = function(x, description = "") {
         ans = shapiro.test(x)
         class(ans) = "list"
         new("hypTest",
           call = match.call(),
           data = x,
           test = ans,
           description = description)
       }
       test = swTest(x = rnorm(500), description = "500 RVs")

    ## Extractor Functions:
       isS4(test)
       getCall(test)
       getDescription(test)

    ## get arguments
    args(returns)
    getArgs(returns)
    getArgs("returns")
    getArgs(returns, "timeSeries")
    getArgs("returns", "timeSeries")

[Package fBasics version 3042.89 Index]