XLISP-STAT allows the construction of normal one way analysis of
variance models. The definitions needed are in the file ` oneway.lsp`
on the distribution disk. This file is not loaded automatically at start
up; you should load it now, using the ** Load** item on the
** File** menu or the ` load` command, to carry out the
calculations in this section.

As an example, suppose we would like to model the data on cholesterol levels in rural and urban Guatemalans, examined in Section 3.2, as a one way ANOVA model. The boxplots we obtained in Section 3.2 showed that the samples were skewed and the center and spread of the urban sample were larger than the center and spread of the rural sample. To compensate for these facts I will use a normal ANOVA model for the logarithms of the data:

> (def cholesterol (oneway-model (list (log urban) (log rural)))) Least Squares Estimates: Group 0 5.377172 (0.03624821) Group 1 5.099592 (0.03456131) R Squared: 0.4343646 Sigma hat: 0.1621069 Number of cases: 42 Degrees of freedom: 40 Group Mean Square: 0.8071994 (1) Error MeanSquare: 0.02627865 (40) CHOLESTEROL >

The function ` oneway-model` requires one argument, a list of the
lists or vectors representing the samples for the different groups. The
model ` cholesterol` can respond to all regression messages as well as
a few new ones. The new ones are

:BOXPLOTS :ERROR-MEAN-SQUARE :ERROR-DF :GROUP-DF :GROUP-MEAN-SQUARE :GROUP-NAMES :GROUP-SUM-OF-SQUARES :GROUPED-DATA :STANDARD-DEVIATIONS

Tue Jan 21 15:04:48 CST 1997