Saves fixed tests from a `REML`

analysis (R.W. Payne).

### Options

`FIXEDTESTS` = pointer |
Saves the fixed tests |
---|---|

`FMETHOD` = string token |
Controls whether and how to calculate F-statistics (`automatic` , `none` , `algebraic` , `numerical` ); default `auto` |

`WMETHOD` = string token |
Controls which tests are saved (`add` , `drop` ); default `drop` |

`SAVE` = `REML` save structure |
Specifies the save structure from the required analysis; default `*` i.e. most recent one |

### No parameters

### Description

`VFIXEDTESTS`

saves the results of the fixed tests in a `REML`

analysis. By default the results are from the most recent `REML`

, but you use the `SAVE`

option to specify the save structure from some other analysis.

The `WMETHOD`

option controls whether the tests are from the table where terms are added sequentially to the model, or that where terms are dropped from the full fixed model.

The `FMETHOD`

option specifies which algorithm to use to calculate the denominator numbers of degrees of freedom required for F tests. The default, automatic, will use any stored values that have been calculated for this analysis by earlier `REML`

, `VDISPLAY`

or `VKEEP`

statements; otherwise it will choose automatically between the two available methods. (See `REML`

for more details.)

The tests are saved, in a pointer, using the `FIXEDTESTS`

option. The pointer is labelled by the headings from the tests for fixed tests that appear in the `REML`

output. If the denominator degrees of freedom are available, the labels and their corresponding vectors are as follows:

`Term` |
text containing the names of the fixed terms, |

`Wald statistic` |
variate containing the Wald statistics, |

`n.d.f.` |
variate containing the numerator degrees of freedom, |

`F statistic` |
variate containing the F statistics, |

`d.d.f.` |
variate containing the denominator degrees of freedom, |

`F pr.` |
variate containing the probabilities for the F tests. |

If the denominator degrees of freedom are not available (either because they could not be calculated, or because `FMETHOD`

has been set to none), the labels `F statistic`

, `d.d.f.`

and `F pr.`

are omitted, and instead there is

`Chi pr.` |
variate containing the probabilities for chi-square tests for the Wald statistics. |

The vectors have an element for each fixed term, with missing values if its test results are unavailable. (For example, with the fixed model `A*B`

, tests for the main effects `A`

and `B`

would be available only when `WMETHOD=add`

.)

Options: `FIXEDTESTS`

, `FMETHOD`

, `WMETHOD`

, `SAVE`

.

Parameters: none.

### See also

Directive: `VKEEP`

.

Procedure: `VSPREADSHEET`

.

Commands for: REML analysis of linear mixed models.

### Example

CAPTION 'VFIXEDTESTS example','Guide Part 2, Example 5.3.6a'; STYLE=meta,plain FACTOR [NVALUES=322; LEVELS=27] Dam & [LEVELS=18] Pup FACTOR [LEVELS=2; LABELS=!T('M','F')] Sex FACTOR [LEVELS=3; LABELS=!T('C','Low','High')] Dose VARIATE [NVALUES=322] Littersize,Weight OPEN '%GENDIR%/Examples/GuidePart2/Rats.dat'; CHANNEL=inchan READ [CHANNEL=inchan] Dose,Sex,Littersize,Dam,Pup,Weight; \ FREPRESENTATION=2(labels),4(levels) CLOSE inchan VCOMPONENTS [FIXED=Littersize+Dose*Sex] RANDOM=Dam/Pup REML Weight VFIXEDTESTS [FIXEDTESTS=Droptests] PRINT Droptests[] VFIXEDTESTS [FIXEDTESTS=Addtests; WMETHOD=add] PRINT Addtests[]