anscombetukey: Test for homogeneity of variances of Anscombe and Tukey

In ExpDes: Experimental Designs Package

Description

anscombetukey Performs the test for homogeneity of variances of Anscombe and Tukey (1963).

Usage

anscombetukey(
  resp,
  Trat,
  Bloco,
  glres,
  msres,
  sstrat,
  ssbloco,
  residuals,
  fitted.values
)

Arguments

resp	Numeric or complex vector containing the response variable.
Trat	Numeric or complex vector containing the treatments.
Bloco	Numeric or complex vector containing the blocks.
glres	Residual degrees of freedom.
msres	Residual Mean Square.
sstrat	Residual Sum of Squares.
ssbloco	Sum of Squares for blocks.
residuals	Numeric or complex vector containing the residuals.
fitted.values	Numeric or complex vector containing the fitted values.

Value

Returns the p-value of Anscombe and Tukey's test of homogeneity of variances and its practical interpretation for 5% of significance.

Author(s)

Eric B Ferreira, [e-mail]

Denismar Alves Nogueira

Marcos Costa de Paula

Mateus Pimenta Siqueira Lima

References

ANSCOMBE, F. J.; TUKEY, J. W. The examination and analysis of residuals. Technometrics, 5:141-160, 1963.

RIBEIRO, R. Proposta e comparacao do desempenho de testes para homogeneidade de variancia de modelos de classificacao one-way e two-way. Iniciacao Cientifica. (Iniciacao Cientifica) - Universidade Federal de Alfenas. 2012.

See Also

han, oneillmathews.

Examples

data(ex2)
attach(ex2)
rbd(trat, provador, aparencia, quali = TRUE, mcomp = "tukey",
hvar='anscombetukey', sigT = 0.05, sigF = 0.05)

Example output

Attaching package: ‘ExpDes’

The following object is masked from ‘package:stats’:

    ccf

------------------------------------------------------------------------
Analysis of Variance Table
------------------------------------------------------------------------
            DF      SS MS     Fc      Pr>Fc
Treatament   4  720.38  2 71.156 0.00000000
Block       69  324.00  4  1.855 0.00025852
Residuals  276  698.55  3                  
Total      349 1742.94  1                  
------------------------------------------------------------------------
CV = 29.14 %

------------------------------------------------------------------------
Shapiro-Wilk normality test
p-value:  0.617668 
According to Shapiro-Wilk normality test at 5% of significance, residuals can be considered normal.
------------------------------------------------------------------------

------------------------------------------------------------------------
Homogeneity of variances test
p-value:  0.9972036 
According to the test of anscombetukey at 5% of significance, the variances can be considered homocedastic.
------------------------------------------------------------------------

Tukey's test
------------------------------------------------------------------------
Groups Treatments Means
a 	 D 	 6.657143 
a 	 E 	 6.6 
a 	 C 	 6.271429 
 b 	 B 	 4.871429 
  c 	 A 	 2.9 
------------------------------------------------------------------------

ExpDes documentation built on Oct. 5, 2021, 9:09 a.m.