Adds terms from a `REML`

fixed model into a Genstat regression (R.W. Payne).

### Options

`PRINT` = string tokens |
Controls printed output (`model` , `deviance` , `summary` , `estimates` , `correlations` , `fittedvalues` , `accumulated` ); default `mode` , `summ` , `esti` , `accu` |

`DENOMINATOR` = string token |
Whether to base ratios in accumulated summary on rms from model with smallest residual ss or smallest residual ms (`ss` , `ms` ); default `ss` |

`SELECTION` = string tokens |
One or two criteria to be printed with the models (`%variance` , `%ss` , `adjustedr2` , `r2` , `dispersion` , `aic` , `sic` , `bic` ); default `%var` , `aic` , `sic` |

### No parameters

### Description

`VRDISPLAY`

displays output from models fitted by procedures `VRFIT`

, `VRADD`

, `VRDROP`

, `VRSWITCH`

and `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). The models are thus assessed against identical estimates of the random variation (as in an analysis of variance), allowing statistics such as the Akaike information criterion to be used to assess which model may be best. Conversely, if you try to assess the fixed model by changing the fixed model in a sequence of `VCOMPONENTS`

commands, the fixed terms that are not fitted will be included in the random variation. This will then vary from fit to fit, making it difficult to reach a clear and consistent conclusion. See `VRFIT`

for more details.

The `PRINT`

option controls printed output as in the regression directives, except that some irrelevant settings are omitted. The available settings are as follows.

`model`

description of the currently fitted model, including response and explanatory variates,

`deviance`

abbreviated summary analysis of variance,

`summary`

summary analysis of variance,

`estimates`

estimates of the parameters in the model,

`correlations`

correlation matrix of the parameter estimates,

`fittedvalues`

table with unit labels, values of response variate, fitted values, standardized residuals and leverages, and

`accumulated`

analysis of variance table showing the various changes that have been made to the model.

The `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.

The `SELECTION`

option specifies the statistics to be displayed in the summary of analysis as in the regression directives, except that again some irrelevant settings are omitted. The available settings are as follows.

`%variance`

percentage variance accounted for by the currently fitted model,

`%ss`

percentage sum of squares accounted for,

`adjustedr2`

proportion of variance accounted for (i.e. `%variance`

/ 100),

`r2`

proportion of the sum of squares accounted for (i.e. `%ss`

/ 100),

`dispersion`

dispersion parameter (which is equal to the residual mean square for an ordinary regression like this),

`aic`

Akaike information criterion, and

`sic`

or `bic`

Schwarz (Bayesian) information criterion.

Options: `PRINT`

, `DENOMINATOR`

, `SELECTION`

.

Parameters: none.

### See also

Directives: `RDISPLAY`

, `REML`

.

Procedures: `VRADD`

, `VRDROP`

, `VRFIT`

, `VRKEEP`

, `VRSETUP`

, `VRSWITCH`

, `VRTRY`

.

Commands for: REML analysis of linear mixed models.

### Example

CAPTION 'VRDISPLAY 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=accumulated] Littersize+Sex*Dose VRDISPLAY [PRINT=estimates]