This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.

# NominalVariables

 NominalVariables is an option for fitting functions such as LinearModelFit that specifies which variables should be treated as having discrete values specified by names.
 Automatic treat variables with non-numeric data values as nominal All treat all variables as nominal None treat no variables as nominal {v1,v2,...} treat the variables as nominal
• In linear models, a nominal variable v with possible values , , ... is represented as a collection of variables with values or corresponding to each case .
Define some data:
Fit the data, treating the first variable as a nominal variable:
See the functional form:
Treat all variables as nominal:
Define some data:
Fit the data, treating the first variable as a nominal variable:
 Out[2]=
See the functional form:
 Out[3]=
Treat all variables as nominal:
 Out[4]=
 Scope   (2)
Automatically select nominal variables:
Specify nominal variables in GeneralizedLinearModelFit:
 Applications   (3)
Fit a one-way ANOVA model:
Obtain the ANOVA table:
Compute the model estimates for the three groups:
Fit a two-way ANOVA model with interaction term:
Obtain the ANOVA table:
Compute estimates for each cell:
Results in a table:
Fit an ANCOVA model:
Visualize curves for the three x categories and label using Tooltip:
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