SMOOTH2 - SMOOTH a uniformly sampled 2d array of data, within a user-defined window, via a damped least squares technique

smooth2 < stdin n1= n2= [optional parameters ] > stdout

Required Parameters:
n1= number of samples in the 1st (fast) dimension
n2= number of samples in the 2nd (slow) dimension

Optional Parameters:
r1=0 smoothing parameter in the 1 direction
r2=0 smoothing parameter in the 2 direction
win=0,n1,0,n2 array for window range
rw=0 smoothing parameter for window function
efile= =efilename if set write relative error(x1) to
efilename

Notes:
Larger r1 and r2 result in a smoother data. Recommended ranges of r1 ",
and r2 are from 1 to 20.

The file verror gives the relative error between the original velocity
and the smoothed one, as a function of depth. If the error is
between 0.01 and 0.1, the smoothing parameters are suitable. Otherwise,
consider increasing or decreasing the smoothing parameter values.

Smoothing can be implemented in a selected window. The range of 1st
dimension for window is from win[0] to win[1]; the range of 2nd
dimension is from win[2] to win[3].

Smoothing the window function (i.e. blurring the edges of the window)
may be done by setting a nonzero value for rw, otherwise the edges
of the window will be sharp.



Credits:
CWP: Zhen-yue Liu,
adapted for par/main by John Stockwell 1 Oct 92
Windowing feature added by Zliu on 16 Nov 1992