prtPreProcLda  Linear discriminant analysis processing
 
    preProc = prtPreProcLda creates a linear discriminant pre
    processing object. A prtPreProcLda object projects the input data
    onto a linear space that best separates class labels
 
    A prtPreProcLda object has the following properties:
 
    nComponents - The number of dimensions to project the data onto.
                  This must less than or equal to the input data's
                  number of features, and less than or equal to the 
                  input data sets number of classes.
 
    A prtPreProcLda object also inherits all properties and functions from
    the prtAction class
 
    More information about LDA can be found at the following URL:
    http://en.wikipedia.org/wiki/Linear_discriminant_analysis
 
    Example:
 
    dataSet = prtDataGenIris;               % Load a dataset
    dataSet = dataSet.retainFeatures(1:3);  % Retain the first 3 features
    lda = prtPreProcLda;                    % Create the pre-processor
 
    lda = lda.train(dataSet);               % Train
    dataSetNew = lda.run(dataSet);          % Run
 
    % Plot the results
    subplot(2,1,1); plot(dataSet);
    title('Original Data');
    subplot(2,1,2); plot(dataSetNew);
    title('LDA Projected Data');