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

Input: 
 x  n x 2, the data. The first column contains the
independent variable, the second one contains the
dependent variable.

 h  scalar, bandwidth. If not given, the rule of thumb
bandwidth computed by lpregrot is used.

 p  optional scalar, order of polynomial:
p = 0: yields the NadarayaWatson estimator.
p = 1: local linear (default).
p = 2: local quadratic, which is the highest possible order.

 v  optional m x 1 vector, values of the independent variable on
which to compute the regression. If not given, the
(sorted) x matrix 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 and the
second column contains the regression estimate
on the values of the first column. 