Program sffastpwd | 2-D dip estimation using analytical equation. 
[SYNOPSIS]
sffastpwd < inp.rsf > out.rsf rect1=1 rect2=1 niter=100 verb=y eps=0.0f
[PARAMETERS]
float   | eps | =0.0f |   | 	regularization 
int     | niter | =100 |   | 	number of iterations 
int     | rect1 | =1 |   | 	
int     | rect2 | =1 |   | 	smoothing radius 
bool    | verb | =y |  [y/n] | 	verbosity 
[DIRECTORY]
user/chen
