    Type            (optional) Method for CF estimation, 'Welch'
                           approach (default) or 'periodogram' approach
           start           (optional) start sample in original data
           stop            (optional) last sample in original data


 Typical application: Operational modal analysis, OMA
 Correlation function can be collected into a matrix for processing by DATA2HMTRX
 by specifying FunctionType = [7 8] 

 See also  <a href="time2spec.html" class="code" title="function