Last data update: 2014.03.03

R: Monte Carlo study of randomized and blocked designs
xdesignR Documentation

Monte Carlo study of randomized and blocked designs

Description

Simulates completely randomized design and randomized block designs from a population of experimental units with underlying response values y and underlying other variable values x (possibly lurking)

Usage

xdesign(x = NULL, y = NULL, corr = 0.8, size = 20, n.treatments = 4,
  n.rep = 500)

Arguments

x

a set of lurking values which are correlated with the response

y

a set of response values

corr

the correlation between the response and lurking variable

size

the size of the treatment groups

n.treatments

the number of treatments

n.rep

the number of Monte Carlo replicates

Value

If the ouput of xdesign is assigned to a variable, then a list is returned with the following components:

block.means

a vector of the means of the lurking variable from each replicate of the simulation stored by treatment number within replicate number

treat.means

a vector of the means of the response variable from each replicate of the simulation stored by treatment number within replicate number

ind

a vector containing the treatment group numbers. Note that there will be twice as many group numbers as there are treatments corresponding to the simulations done using a completely randomized design and the simulations done using a randomized block design

Examples


# Carry out simulations using the default parameters 

xdesign()

# Carry out simulations using a simulated response with 5 treaments, 
# groups of size 25, and a correlation of -0.6 between the response 
# and lurking variable

xdesign(corr = -0.6, size = 25, n.treatments = 5)

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

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Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(Bolstad)

Attaching package: 'Bolstad'

The following objects are masked from 'package:stats':

    IQR, sd, var

> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/Bolstad/xdesign.Rd_%03d_medium.png", width=480, height=480)
> ### Name: xdesign
> ### Title: Monte Carlo study of randomized and blocked designs
> ### Aliases: xdesign
> ### Keywords: misc
> 
> ### ** Examples
> 
> 
> # Carry out simulations using the default parameters 
> 
> xdesign()
Variable	N	Mean	Median	TrMean	StDev	SE Mean
X		80	-0.119	-0.086	-0.106	1.138	0.127
Y		80	-0.132	-0.035	-0.116	1.119	0.125

Variable	Minimum	Maximum	Q1	Q3
X		-2.831	2.528	-0.893	0.734
Y		-2.373	2.457	-1.012	0.784

The Pearson correlation between X and Y is: 0.838 

Variable	N	Mean	Median	TrMean	StDev	SE Mean
Randomized	2000	-0.132	-0.128	-0.131	0.215	0.005
Blocked		2000	-0.132	-0.137	-0.133	0.117	0.003

Variable	Minimum	Maximum	Q1	Q3
Randomized	-0.922	0.633	-0.279	0.013
Blocked		-0.48	0.247	-0.216	-0.053

> 
> # Carry out simulations using a simulated response with 5 treaments, 
> # groups of size 25, and a correlation of -0.6 between the response 
> # and lurking variable
> 
> xdesign(corr = -0.6, size = 25, n.treatments = 5)
Variable	N	Mean	Median	TrMean	StDev	SE Mean
X		125	0.006	-0.002	0.021	0.86	0.077
Y		125	-0.004	0.013	0	0.98	0.088

Variable	Minimum	Maximum	Q1	Q3
X		-2.944	2.42	-0.482	0.586
Y		-3.203	2.377	-0.657	0.693

The Pearson correlation between X and Y is: -0.473 

Variable	N	Mean	Median	TrMean	StDev	SE Mean
Randomized	2500	-0.004	-0.003	-0.004	0.175	0.003
Blocked		2500	-0.004	0.001	-0.002	0.157	0.003

Variable	Minimum	Maximum	Q1	Q3
Randomized	-0.564	0.589	-0.125	0.114
Blocked		-0.532	0.448	-0.105	0.103

> 
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>