 Usage:  y = lpregxest (x,h {,p {,v}})  
 
 Input:

  x                      n x 2, the data. In the first column the 
                         independent, in the second column the 
                         dependent variable. 
                         
  h                      scalar, bandwidth. If not given, the rule of thumb 
                         bandwidth computed by lpregrot is used. 
                         
  p                      integer, order of polynomial. If not given, 
                         p=1 (local linear) is used. p=0 yields the 
                         Nadaraya-Watson estimator. p=2 (local 
                         quadratic) is the highest possible order. 
                         
  v                      m x 1, values of the independent variable on 
                         which to compute the regression. If not given, 
                         x is used. 
                         
 Output:

  mh                     n x 2 or m x 2 matrix, the first column is the 
                         sorted first column of x or the sorted v, the 
                         second column contains the regression estimate 
                         on the values of the first column. 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
