STK_FACTORIALDESIGN constructs a "full factorial design" array

 CALL: D = stk_factorialdesign (LEVELS)

   creates a full factorial design with levels LEVELS{1} for the first
   variable, LEVELS{2} for the second variable, etc.  The output is an object
   of the stk_factorialdesign class, which derives from stk_dataframe.

 CALL: D = stk_factorialdesign (LEVELS, COLNAMES)

    allows to specify column names for the dataframe D.

 CALL: D = stk_factorialdesign (LEVELS, COLNAMES, ROWNAMES)

    allows to specify row names as well.

 See also: stk_dataframe, stk_hrect