 Usage:  mh = regxest(x {,h {,K} {,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, 20% of the 
                         range of x[,1] is used. 
                         
  K                      string, kernel function on [-1,1] or Gaussian 
                         kernel "gau". If not given, the Quartic kernel 
                         "qua" is used. 
                         
  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
