 Usage:  {at, bt} = sure (a, b)  
 
 Input:

  a                      p x 2 array, indices and coefficients of the father wavelet 
                         
  b                      q x 3 array, indices and coefficients of mother wavelet 
                         
 Output:

  at                     p x 2 array, thresholded father wavelet coefficients 
                         
  bt                     q x 3 array, thresholded mother wavelet coefficients 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
