 Usage:  z = zxgen(serie,beginn,ende,order,meanadj)  
 
 Input:

  serie                  N x K matrix 
                         
  beginn                 integer, >= order 
                         
  ende                   integer, >= beginn 
                         
  order                  integer 
                         
  meanadj                scalar, 1=is mean adjusted, 0=is not 
                         
 Output:

  z                      matrix, dimension depends on meanadj 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
