Saves output for a
REML fixed model fitted in a Genstat regression (R.W. Payne).
||Limit for expansion of terms; default 3|
||Residuals, as specified by the
||Type of residuals to form (
||Residual degrees of freedom|
||Residual sum of squares|
||Accumulated analysis-of-variance table|
||Whether to base ratios in accumulated summary on rms from model with smallest residual ss or smallest residual ms (
||Terms whose information is to be saved|
||Estimated regression coefficients for each term|
||Standard errors of estimated regression coefficients for each term|
||Variances and covariances between the estimates of each term|
||Numerator degrees of freedom for each term|
||Denominator degrees of freedom for each term|
VRKEEP saves output from models fitted by procedures
VRTRY, which are designed to improve the process of determining the appropriate fixed terms to include in a
REML analysis. They do this by a generalized regression analysis, with a weight matrix based on variances estimated from the original
REML analysis (with the full fixed model). See
VRFIT for more details.
TERMS parameter specifies terms about which you wish to save information. As in
FACTORIAL option sets a limit on the number of factors and variates 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 the various types of information for each of the terms that you have specified. The
ESTIMATES parameter saves estimates for each term, in a table if the term involves factors or in a scalar if it involves only variates. Similarly the
SE parameter saves standard errors for the estimates. The
VCOVARIANCE parameter saves the variances and covariances between the estimates of each term, in a symmetric matrix if the term involves factors or in a scalar if it involves only variates. The
DDF parameters saves the number of numerator and denominator degrees of freedom for the terms, in scalars. If you have a single term, you can supply a table, scalar 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, scalars or symmetric matrices as there are terms.
FITTEDVALUES options save the residuals and fitted values, respectively. The
RMETHOD option controls the type of residuals that are formed.
RSS options save the number of residual degrees of freedom and the residual sum of squares.
ACCUMULATED parameter saves the accumulated analysis-of-variance table, as a pointer with elements labelled ‘
Wald pr.’, ‘
d.d.f.’ and ‘
F pr.‘. The last two elements will contain missing values if the denominator degrees of freedom of the terms could not be estimated in the original
REML analysis. The pointer is defined so that the case of the labels is not significant.
DENOMINATOR option specifies how the residual is selected for the accumulated analysis of variance By default it is taken from the model with the smallest number of residual degrees of freedom. However, you can set
DENOMINATOR=ms to take it from the model with the smallest residual mean square.
CAPTION 'VRKEEP example',\ 'Example 5.3.6 from The Guide to Genstat, Part 2 Statistics';\ STYLE=meta,plain FACTOR [NVALUES=322; LEVELS=27] Dam & [NVALUES=322; LEVELS=18] Pup FACTOR [NVALUES=322; LEVELS=2; LABELS=!T('M','F')] Sex FACTOR [NVALUES=322; LEVELS=3; LABELS=!T('C','Low','High')] Dose VARIATE [NVALUES=322] Littersize,Weight OPEN '%GENDIR%/Examples/GuidePart2/Rats.dat'; CHANNEL=chan READ [CHANNEL=chan] Dose,Sex,Littersize,Dam,Pup,Weight; \ FREPRESENTATION=2(labels),4(levels) CLOSE chan VCOMPONENTS [FIXED=Littersize+Dose*Sex] RANDOM=Dam/Pup REML [PRINT=model,components,wald] Weight VRFIT [PRINT=estimates,accumulated] Littersize+Sex*Dose VRKEEP [ACCUMULATED=accumulated] Littersize+Sex+Dose;\ ESTIMATES=!p(lest,sest,dest); SE=!p(lse,sse,dse);\ DDF=!p(lddf,sddf,dddf) PRINT accumulated & lest,lse,lddf & sest,sse & sddf & dest,dse & dddf