Learn R Programming

rcompanion (version 1.13.2)

rcompanion-package: rcompanion: Functions to support extension education program evaluation

Description

This package provides custom functions for working through examples and analyses from "Summary and Analysis of Extension Education Program Evaluation in R" and "An R Companion for the Handbook of Biological Statistics".

Arguments

Useful functions

The function nagelkerke provides pseudo R-squared values for a variety of model types, as well as a likelihood ratio test for the model as a whole. An addtional function, nagelkerkeHermite, is provided for models fit with the hermite package.

There are several functions that provide summary statistics for grouped data. These function titles tend to start with "groupwise". They provide means, medians, geometric means, and Huber M-estimators for groups, along with confidence intervals by traditional methods and bootstrap.

Function titles starting with "pairwise" conduct pairwise tests among groups as a post-hoc analysis for omnibus tests. At the time of writing, these tests are Mood's median test, sign test (for omnibus Friedman test), permutation test, robust anova, and ordinal regression. The output is a table of comparisons and p-values, or a matrix of p-values that can be parsed into a compact letter display.

There are also functions that are useful for comparing models. compareLM, compareGLM, and pairwiseModelAnova. These use goodness-of-fit measures like AIC, BIC, and BICc, or likelihood ratio tests.

There are a few useful plotting functions, including plotNormalHistogram that plots a histogram of values and overlays a normal curve, and plotPredy which plots of line for predicted values for a bivariate model. Other plotting functions include producing density plots.

Functions for nominal data include post-hoc tests for Cochran-Mantel-Haenszel test (groupwiseCMH), for McNemar-Bowker test (pairwiseMcnemar), and for tests of association like Chi-square, Fisher exact, and G-test (pairwiseNominalIndependence).

A function close to my heart is (cateNelson), which performs Cate-Nelson analysis for bivariate data.

Vignettes and examples

The functions in this package are used in "Extension Education Program Evaluation in R" which is available at http://rcompanion.org/handbook/ and "An R Companion for the Handbook of Biological Statistics" which is available at http://rcompanion.org/rcompanion/.

The documentation for each function includes an example as well.