 Usage:  y = pgram(x {,opt})  
 
 Input:

  x                      vector 
                         
  opt (optional)         integer; If opt=1 (Default) the periodogram is returned, 
                         otherwise the log periodogram 
                         
 Output:

  y                      vector 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
