Learn R Programming

fBasics (version 4041.97)

getS4: General S4 Class Extractor Functions

Description

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

The extractor functions are:

getModelExtracts the model slot from a S4 object,
getTitleExtracts the title slot from a S4 object,
getDescriptionExtracts the description slot from a S4 object,
getSlotExtracts a specified slot from a S4 object,
getArgsShows 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)

Value

for

getModel, getTitle, getDescription, and

getSlot

- the content of the corresponding slot.

for getArgs the names of the arguments.

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.

Examples

Run this code
## 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")

Run the code above in your browser using DataLab