Analysis of variance


GenStat has a comprehensive set of commands for analysis of variance. The following directives define the models to be fitted:


BLOCKSTRUCTURE
defines the blocking structure of the design, and hence the strata and error terms

COVARIATE
specifies covariates for analysis of covariance

TREATMENTSTRUCTURE
defines the treatment (or systematic) terms


For unstructured designs with a single error term, BLOCKSTRUCTURE need not be specified, and COVARIATE is needed only for analysis of covariance. Balanced designs can be analysed using the ANOVA directive.


ANOVA
performs analysis of variance


Directives are available to produce further output from an ANOVA analysis, or to save information in GenStat data structures:


ADISPLAY
displays further output from analyses produced by ANOVA

AKEEP
copies information from an ANOVA analysis into GenStat data structures


Unbalanced designs with a single error term can be be analysed using the AUNBALANCED procedure.


AUNBALANCED
performs analysis of variance for unbalanced designs

AUDISPLAY
produces further output for an unbalanced design (after AUNBALANCED)

AUKEEP
saves output from analysis of an unbalanced design (by AUNBALANCED)


Other procedures relevant to analysis of variance include:


AGRAPH
plots one- or two-way tables of means from ANOVA

APLOT
plots residuals from an ANOVA analysis

AFIELDRESIDUALS
display residuals in field layout

AFCOVARIATES
defines covariates from a model formula for ANOVA

ASTATUS
provides information about the settings of ANOVA models and variates

APERMTEST
does random permutation tests for analysis-of-variance tables

A2WAY
performs analysis of variance of a balanced or unbalanced design with up to two treatment factors

A2DISPLAY
provides further output following an analysis of variance by A2WAY

A2KEEP
copies information from an A2WAY analysis into GenStat data structures

ABIVARIATE
produces graphs and statistics for bivariate analysis of variance

ALIAS
finds out information about aliased model terms in analysis of variance

AMCOMPARISON
performs pairwise multiple comparison tests for ANOVA means

AMDUNNETT
forms Dunnett's simultaneous confidence interval around a control

AMTIER
analyses a multitiered design by analysis of variance specified by up to 3 model formulae

AMTDISPLAY
displays further output for multitiered designs analysed by AMTIER

APOLYNOMIAL
forms the equation for a polynomial contrast fitted by ANOVA

AREPMEASURES
produces an analysis of variance for repeated measurements

ASCREEN
performs screening tests for designs with orthogonal block structure

MAANOVA
does analysis of variance for a single-channel microarray design (parallel anova)

CONFIDENCE
calculates simultaneous confidence intervals

SED2ESE
calculates effective standard errors that give good approximate standard errors of differences

SEDLSI
calculates least significant intervals

LSIPLOT
plots least significant intervals, saved from SEDLSI

RTCOMPARISONS
calculates comparison contrasts within a multi-way table of means

A2PLOT
plots effects and robust s.e. estimates from designs with two-level factors

CENSOR
pre-processes censored data before analysis by ANOVA

CINTERACTION
clusters rows and columns of a two-way interaction table

DIALLEL
analyses full and half diallel tables with parents

AMMI
allows exploratory analysis of genotype × environment interactions

FRIEDMAN
performs Friedman's nonparametric analysis of variance

NLCONTRASTS
fits non-linear contrasts to quantitative factors in ANOVA

VHOMOGENEITY
tests homogeneity of variances

WSTATISTIC
calculates the Shapiro-Wilk test for Normality