60 rats were fed varying diets to see which produced the greatest weight gain.  Two diet factors were protein type: beef, pork, chicken and protein level: high and low.

datasets

This small collection of functions provides distinctive
        graphics for display of anova results. The two principal
        functions are granova.1w (a graphic for one way anova) and
        granova.2w (a corresponding graphic for two way anova). These
        functions were written to display data for any number of
        groups, regardless of their sizes (however, very large data
        sets or numbers of groups are likely to be problematic). For
        these two functions a specialized approach is used to construct
        data-based contrast vectors with respect to which anova data
        are displayed. The result is that the graphics use straight
        lines, and flat surfaces, to help ensure clear interpretations
        while being faithful to the standard effect tests in anova; the
        graphic results are complementary to standard summary tables
        for these two basic kinds of analysis of variance. Two
        additional functions are granova.ds (for comparing two
        dependent samples of data), and granova.contr (which provides
        graphic displays for a priori contrasts). All functions provide
        relevant numerical results to supplement the graphic displays
        of anova data. The graphics based on these functions are aimed
        at students and non-statistician analysts; but they can be
        generally helpful for identifying outliers, clusters, trends or
        the role of non-linear transformations of data. In the case of
        granova.1w and granova.ds especially, several arguments have
        been provided to facilitate construction of graphics that
        accommodate diverse features of data, and their corresponding
        display requirements.

James Helmreich

granova

Graphical Analysis of Variance

rat function

docType

Fundamentals of Exploratory Analysis of Variance, Hoaglin D., Mosteller F. and Tukey J. eds., Wiley, 1991, p. 100; originally from Statistical Methods, 7th ed, Snedecor G. and Cochran W. (1980), Iowa State Press.

rat: Weight gains of rats fed different diets

Description

Usage

Arguments

docType

source