derive {cNORM} | R Documentation

## Derivative of regression model

### Description

Calculates the derivative of the location / norm value from the regression model with the first derivative as the default. This is useful for finding violations of model assumptions and problematic distribution features as f. e. bottom and ceiling effects, non-progressive norm scores within an age group or in general #' intersecting percentile curves.

### Usage

    derive(model, order = 1, covariate = NULL)

### Arguments

`model` | The regression model or a cnorm object
`order` | The degree of the derivate, default: 1
`covariate` | In case, a covariate has been used, please specify the degree of the covariate / the specific value here.

### Value

The derived coefficients

### See Also

Other model: `bestModel()`, `checkConsistency()`, `cnorm.cv()`, `modelSummary()`, `print.cnorm()`, `printSubset()`, `rangeCheck()`, `regressionFunction()`, `summary.cnorm()`

### Examples

    normData <- prepareData(elfe)
    m <- bestModel(normData)
    derivedCoefficients <- derive(m)

[Package cNORM version 2.0.3 Index]