 Usage:  y = shiftr(x,a,b)  
 
 Input:

  x                      matrix (n x k) 
                         
  a                      vector (n x 1) or (1 x 1) 
                         gives amount of shift per row 
                         
  b                      vector (n x 1) or (1 x 1) 
                         values that are used to fill up 
                         
 Output:

  y                      matrix with rows shifted to the right by a and 
                         filled with b 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
