# SattDF: Satterthwaite Approximation for Total Degrees of Freedom and... In VCA: Variance Component Analysis

## Description

This function estimates degrees of freedom of the total variance (type="total") in random models or individual variance components (type="individual"). It bases on the results of the unified approach to ANOVA-type estimation of variance components as implemented in functions `anovaVCA` and `anovaMM`.

## Usage

 `1` ```SattDF(MS, Ci, DF, type = c("total", "individual")) ```

## Arguments

 `MS` (numeric) vector of sequential mean squares (ANOVA type-1). `Ci` (matrix) where elements are numeric values representing the inverse of the coefficient matrix for calculation of expected mean squares (see `anovaVCA`, `getCmatrix`). `DF` (numeric) vector with the degrees of freedom for each factor in a ANOVA type-1 model. `type` (character) string specifying whether "total" degrees of freedom should be approximated or those of individual variance components

## Details

Function is used internally, thus, it is not exported. Option 'type="total"' is used in functions `anovaVCA` and `anovaMM` for approximating total DF. Option 'type="individual"' is used in function `VCAinference` when choosing 'ci.method="satterthwaite"' for approximating DFs for individual variance components.

## Value

numeric value representing the Satterthwaite DFs of the total variance.

## Author(s)

Andre Schuetzenmeister [email protected]

## Examples

 ```1 2 3 4 5 6 7 8 9``` ```## Not run: data(dataEP05A2_2) res <- anovaVCA(y~day/run, dataEP05A2_2) VCA:::SattDF(res\$aov.tab[-1,"MS"], getMat(res, "Ci.MS"), res\$aov.tab[-1,"DF"], type="tot") # now approximating individual DF for variance components VCA:::SattDF(res\$aov.tab[-1,"MS"], getMat(res, "Ci.MS"), res\$aov.tab[-1,"DF"], type="i") ## End(Not run) ```

VCA documentation built on July 19, 2018, 5:05 p.m.