AUKEEP procedure

Saves output from analysis of an unbalanced design (by AUNBALANCED) (R.W. Payne).


Options

FACTORIAL = scalar
Limit on number of factors in the model terms generated from the TERMS parameter; default 3

RESIDUALS = variate
To save residuals from the analysis

FITTEDVALUES = variate
To save fitted values

COMBINATIONS = string
Factor combinations for which to form predicted means (present, estimable); default esti

ADJUSTMENT = string
Type of adjustment to be made when predicting means (marginal, equal, observed); default marg

LSDLEVEL = scalar
Significance level (as a percentage) for the least significant differences

RMETHOD = string
Type of residuals to form if the RESIDUALS option is set (simple, standardized); default simp

SAVE = identifier
Save structure (from AUNBALANCED) containing details of the analysis for which further output is required; if omitted, output is from the most recent use of AUNBALANCED


Parameters

TERMS = formula
Model terms for which information is required

MEANS = table or pointer to tables
Predicted means for each term


SEMEANS = table or pointer to tables
Standard errors of the means for each term

SEDMEANS = symmetric matrix or pointer to symmetric matrices
Standard errors of differences between means

ESEMEANS = table or pointer to tables
Approximate effective standard errors of the means: these are formed by procedure SED2ESE with the aim of allowing good approximations to the standard errors for differences to be calculated by the usual formula sedi,j = √( esei2 + esej2 )

LSD = symmetric matrix or pointer to symmetric matrices
Least significant differences


Description

This procedure can be used, following the use of procedure AUNBALANCED, to save output for the analysis of variance of an unbalanced design.

   Options are provided to save information about the analysis as a whole. The RESIDUALS and FITTEDVALUES options allow variates to be specified to store the residuals and fitted values, respectively. The RMETHOD option controls whether simple or standardized residuals are saved; by default RMETHOD=simple.

   The SAVE option can be set to the save structure from the analysis from which output is to be saved. If SAVE is not set, output will be produced for the most recent analysis from AUNBALANCED; however, none of the GenStat regression directives (MODEL, TERMS, FIT, ADD, DROP and so on) must then have been used in the interim.

   The parameters of AUKEEP save information about particular model terms in the analysis. With the TERMS parameter you specify a model formula, which GenStat expands to form the series of model terms about which you wish to save information. As in AUNBALANCED, the FACTORIAL option sets a limit on the number of factors in each term. Any term containing more than that limit is deleted. The subsequent parameters allow you to specify identifiers of data structures to store various components of information for each of the terms that you have specified. The MEANS parameter saves tables of predicted means, the SEMEANS parameter saves tables of standard errors for the means, the SEDMEANS parameter saves symmetric matrices of standard errors of differences, the ESEMEANS parameter saves tables of approximate effective standard errors, and the LSD parameter saves symmetric matrices of least significant differences. If you have a single term, you can supply a table or symmetric matrix for each of these parameters, as appropriate. However, if you have several terms, you must supply a pointer which will then be set up to contain as many tables or symmetric matrices as there are terms. The LSDLEVEL option sets the significance level (as a percentage) for the least significant differences.

   Tables of means are calculated using the PREDICT directive. The first step (A) of the calculation forms the full table of predictions, classified by every factor in the model. The second step (B) averages the full table of over the factors that do not occur in the table of means. The COMBINATIONS option specifies which cells of the full table are to be formed in Step A. The default setting, estimable, fills in all the cells other than those that involve parameters that cannot be estimated, for example because of aliasing. Alternatively, setting COMBINATIONS=present excludes the cells for factor combinations that do not occur in the data. The ADJUSTMENT option then defines how the averaging is done in Step B. The default setting, marginal, forms a table of marginal weights for each factor, containing the proportion of observations with each of its levels; the full table of weights is then formed from the product of the marginal tables. The setting equal weights all the combinations equally. Finally, the setting observed uses the WEIGHTS option of PREDICT to weight each factor combination according to its own individual replication in the data.

 

Options: FACTORIAL, RESIDUALS, FITTEDVALUES, COMBINATIONS, ADJUSTMENT, LSDLEVEL, RMETHOD, SAVE.

Parameters: TERMS, MEANS, SEMEANS, SEDMEANS, ESEMEANS, LSD.


Method

The output is obtained mainly using the directives RKEEP and PREDICT.


Action with RESTRICT

If the y-variate originally analysed by AUNBALANCED was restricted, only the units not excluded by the restriction will have been analysed.