simFrame (version 0.5.4)

TwoStageControl-class: Class "TwoStageControl"

Description

Class for controlling the setup of samples using a two-stage procedure.

Usage

TwoStageControl(…, fun1 = srs, fun2 = srs, size1 = NULL, 
                size2 = NULL, prob1 = NULL, prob2 = NULL, 
                dots1 = list(), dots2 = list())

Arguments

…

the slots for the new object (see below).

fun1

the function to be used for sampling in the first stage (the first list component of slot fun).

fun2

the function to be used for sampling in the second stage (the second list component of slot fun).

size1

the number of PSUs to sample in the first stage (the first list component of slot size).

size2

the number of items to sample in the second stage (the second list component of slot size).

prob1

the probability weights for the first stage (the first list component of slot prob).

prob2

the probability weights for the second stage (the second list component of slot prob).

dots1

additional arguments to be passed to the function for sampling in the first stage (the first list component of slot dots).

dots2

additional arguments to be passed to the function for sampling in the second stage (the second list component of slot dots).

Objects from the Class

Objects can be created by calls of the form new("TwoStageControl", ...) or via the constructor TwoStageControl.

Slots

design:

Object of class "BasicVector" specifying variables (columns) to be used for stratified sampling in the first stage.

grouping:

Object of class "BasicVector" specifying grouping variables (columns) to be used for sampling primary sampling units (PSUs) and secondary sampling units (SSUs), respectively.

fun:

Object of class "list"; a list of length two containing the functions to be used for sampling in the first and second stage, respectively (defaults to srs for both stages). The functions should return a vector containing the indices of the sampled items.

size:

Object of class "list"; a list of length two, where each component contains an optional non-negative integer giving the number of items to sample in the first and second stage, respectively. In case of stratified sampling in the first stage, a vector of non-negative integers, each giving the number of PSUs to sample from the corresponding stratum, may be supplied. For the second stage, a vector of non-negative integers giving the number of items to sample from each PSU may be used.

prob:

Object of class "list"; a list of length two, where each component gives optional probability weights for the first and second stage, respectively. Each component may thereby be a numerical vector, or a character string or integer vector specifying a variable (column) that contains the probability weights.

dots:

Object of class "list"; a list of length two, where each component is again a list containing additional arguments to be passed to the corresponding function for sampling in fun.

k:

Object of class "numeric"; a single positive integer giving the number of samples to be set up.

Extends

Class "'>VirtualSampleControl", directly. Class "'>OptSampleControl", by class "VirtualSampleControl", distance 2.

Accessor and mutator methods

In addition to the accessor and mutator methods for the slots inherited from "'>VirtualSampleControl", the following are available:

getDesign

signature(x = "TwoStageControl"): get slot design.

setDesign

signature(x = "TwoStageControl"): set slot design.

getGrouping

signature(x = "TwoStageControl"): get slot grouping.

setGrouping

signature(x = "TwoStageControl"): set slot grouping.

getCollect

signature(x = "TwoStageControl"): get slot collect.

setCollect

signature(x = "TwoStageControl"): set slot collect.

getFun

signature(x = "TwoStageControl"): get slot fun.

setFun

signature(x = "TwoStageControl"): set slot fun.

getSize

signature(x = "TwoStageControl"): get slot size.

setSize

signature(x = "TwoStageControl"): set slot size.

getProb

signature(x = "TwoStageControl"): get slot prob.

setProb

signature(x = "TwoStageControl"): set slot prob.

getDots

signature(x = "TwoStageControl"): get slot dots.

setDots

signature(x = "TwoStageControl"): set slot dots.

Methods

In addition to the methods inherited from "'>VirtualSampleControl", the following are available:

clusterSetup

signature(cl = "ANY", x = "data.frame", control = "TwoStageControl"): set up multiple samples on a cluster.

setup

signature(x = "data.frame", control = "TwoStageControl"): set up multiple samples.

show

signature(object = "TwoStageControl"): print the object on the R console.

UML class diagram

A slightly simplified UML class diagram of the framework can be found in Figure 1 of the package vignette An Object-Oriented Framework for Statistical Simulation: The R Package simFrame. Use vignette("simFrame-intro") to view this vignette.

Details

There are some restrictions on the argument names of the functions for sampling in fun. If the sampling method needs population data as input, the corresponding argument should be called x and should expect a data.frame. If it only needs the population size as input, the argument should be called N. Note that the function is not expected to have both x and N as arguments, and that the latter is typically much faster. Furthermore, if the function has arguments for sample size and probability weights, they should be called size and prob, respectively. Note that a function with prob as its only argument is perfectly valid (for probability proportional to size sampling). Further arguments may be supplied as a list via the slot dots.

See Also

"'>VirtualSampleControl", "'>SampleControl", "'>SampleSetup", setup, draw

Examples

# NOT RUN {
<!-- % TODO: examples for two-stage sampling -->
# }
# NOT RUN {
showClass("TwoStageControl")
# }