SUTVBAND - time-variant bandpass filter (sine-squared taper)  

 sutvband <stdin >stdout tf= f=			        

 Required parameters:                                          
       dt = (from header)      time sampling interval (sec)    
       tf=             times for which f-vector is specified   
       f=f1,f2,f3,f4   Corner frequencies corresponding to the 
                       times in tf. Specify as many f= as      
                       there are entries in tf.                

 The filters are applied in frequency domain.                  

 Example:                                                      
 sutvband <data tf=.2,1.5 f=10,12.5,40,50 f=10,12.5,30,40 | ...

 Credits:
      CWP: Jack, Ken

 Trace header fields accessed:  ns, dt, delrt