 Usage:  xt = trimper(x,perc)  
 
 Input:

  x                      n x d matrix , the data matrix 
                         In the first row the values according 
                         to which the trimming should be done 
                         are expected. The second row should contain ; the frequency count for the values in the ; first row. 
                         
  perc                   scalar , the percentage of data points which should 
                         be trimmed maximal 
                         
 Output:

  xt                     l x d matrix , the trimmed data matrix 
                         
--------------------------------------------------------------
(C) MD*TECH Method and Data Technologies, 17.8.2000
