prtPreProcZmuv   Zero mean unit variance processing
 
    ZMUV = prtPreProcZmuv creates a zero mean unit variance pre
    processing object. A prtPreProcZmuv object processes the input data
    so that it has zero mean and unit variance.  Use TRAIN to determine
    the parameters of the ZMUV object:
  
    zmuv = prtPreProcZmuv;
    zmuv = zmuv.train(ds); 
 
    And use RUN to process a data set:
 
    dsPreProc = zmuv.run(ds);
 
    A prtPreProcZmuv object also inherits all properties and functions from
    the prtAction class
 
    Example:
 
    dataSet = prtDataGenIris;       % Load a data set.
    dataSet = dataSet.retainFeatures(1:2);
    zmuv = prtPreProcZmuv;           % Create a zero-mean unit variance
                                     % object
    zmuv = zmuv.train(dataSet);      % Compute the mean and variance
    dataSetNew = zmuv.run(dataSet);  % Normalize the data
  
    % Plot
    subplot(2,1,1); plot(dataSet);
    title(sprintf('Mean: %s; Stdev: %s',mat2str(mean(dataSet.getObservations),2),mat2str(std(dataSet.getObservations),2)))
    subplot(2,1,2); plot(dataSetNew);
    title(sprintf('Mean: %s; Stdev: %s',mat2str(mean(dataSetNew.getObservations),2),mat2str(std(dataSetNew.getObservations),2)))