SECTION./LINE
REGRESSION/LINEAR table y x1,x2,...
	linear regression on table columns
SECTION./POLY
REGRESSION/POLY table y x1[,x2] d1[,d2]
	polynomial fit on table columns
SECTION./ROBUST
REGRESSION/ROBUST  tab y  x1[,x2,..,xn] [file] [out_col] [res_col]
	Robust multi-variate regression by Least Median of Squares
SECTION./TABL
REGRESSION/TABLE table1 x1[,x2] table2 y1[,y2] degree tol [guess]
	polynomial fit of variables in two tables (not yet implemented)
