matlab routine

type patch_error from Matlab working window to get a help

color specification is the same as in any Matlab routine

hatching style:        'h' -horizontal
                                'v' - vertical
                                'R' - right inclined ( upper case in difference from 'r' -red)
                                 'l' - left inclined
                                 'n' - no line shading
any combination of line specification indeces does overlay. Example shown in the lower panel corresponds to  'Rl' case