derive function

Derivative of regression model

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.

derive(model, order = 1)

Arguments

• model: The regression model or a cnorm object
• order: The degree of the derivate, default: 1

Returns

The derived coefficients

Examples

m <- cnorm(raw = elfe$raw, group = elfe$group)
derivedCoefficients <- derive(m)

See Also

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