determiningLambda {PhenStat} | R Documentation

## Method "determiningLambda"

### Description

Function role 1. Rescale data if needed (Box-Cox transformation can only be applied on data >0) 2. Calculate lambda value for a Box-Cox transformation 3. Assess whether transformation is required (if confidence interval includes 1 then no transformation required) 4. Return output to allow application of the transformation if necessary using the returned lambda value and any associated rescaling that was needed. 5. Requires a function that will be fitted determined from formulaAssessingBoxCox

### Usage

        determiningLambda(phenList,
    					depVariable,
    					equation="withWeight")

### Arguments

`phenList` | instance of the `PhenList` class; mandatory argument
`depVariable` | a character string defining the dependent variable of interest; mandatory argument
`equation` | a character string defining the equation to use. Possible values "withWeight" (default),"withoutWeight"

### Value

Returns a vector with five elements: 1. 95 2. Midepoint of the 95 3. Calculated lambda value 4. TransformationRequired: TRUE/FALSE 5. Calculated scale shift value

### Author(s)

Natasha Karp

### Examples

            file <- system.file("extdata", "test1.csv", package="PhenStat")
            test <- PhenStat:::PhenList(dataset=read.csv(file,na.strings = '-'),
                    testGenotype="Sparc/Sparc")
            PhenStat:::determiningLambda(test,"Lean.Mass",equation="withoutWeight")

[Package PhenStat version 2.26.0 Index]