getKappa: Calculate the condition number of a set of covariates.

In studyvin/pollinatorAttractiveness: Pollinator Attractiveness Analysis

Description

Calculate the condition number of a set of covariates.

Usage

getKappa(x, df)

Arguments

x	A character string containing covariates present in df, separated by " + ".
df	A dataframe containing the data to be used for subsequent modeling.

Details

Included covariates stored as class factor within df are expanded via function model.matrix via the use of reference-cell coding. Thus, a k-level factor contributes k - 1 variables in the design matrix ultimately used in modeling.

Currently, the function does not check if each variable within x is actually contained within df.

Value

The condition number, a number within the range 1,∞).

Author(s)

WEST, Inc.

References

Belsley, D.A., Kuh, E., and Welsch, R. E. (1980). Regression Diagnostics: Identifying Influential Data and Sources of Collinearity. New York, NY: John Wiley \& Sons, Inc.

studyvin/pollinatorAttractiveness documentation built on Dec. 23, 2021, 6:38 a.m.