TwoStageSampleControl-class: Class '"TwoStageSampleControl"'

Description Usage Arguments Objects from the Class Slots Details Extends Accessor methods Methods UML class diagram Author(s) See Also

Description

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

Usage

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TwoStageSampleControl(..., fun1 = srs, fun2 = srs, 
                      size1 = NULL, size2 = NULL, 
                      prob1 = character(), prob2 = character(), 
                      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 via the constructor TwoStageSampleControl or by calls of the form SampleControl(..., sub = "TwoStage").

Slots

design:

An optional character, integer or logical vector specifying variables (columns) to be used for stratified sampling in the first stage.

grouping:

An character, integer or logical vector specifying grouping variables (columns) to be used for sampling primary sampling units (PSUs) and, optionally, secondary sampling units (SSUs).

fun:

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:

A list of length two, in which 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:

A list of length two, with components optionally specifying variables (columns) that contain probability weights for the first and second stage, respectively.

dots:

A list of length two, in which each component is again a list containing additional arguments to be passed to the corresponding function for sampling in fun.

k:

A positive integer giving the number of samples to be set up.

seed:

An optional integer to be used as initial seed of the random number generator.

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.

Extends

Class "SampleControl", directly. Class "VirtualSampleControl", distance 2. Class "OptSampleControl", distance 3.

Accessor methods

The following accessor methods are available in addition to the inherited ones:

getCollect

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

getFun

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

getSize

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

getProb

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

getDots

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

Methods

The following methods are available in addition to the inherited ones:

setup

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

show

signature(object = "TwoStageSampleControl"): 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.

Author(s)

Andreas Alfons

See Also

"BasicSampleControl", "SampleSetup", setup, draw


aalfons/simFrame documentation built on June 3, 2017, 10:52 a.m.