ERRORBAR

        [GREG1\]ERRORBAR Argument [Array_X Array_Y Array_Z [Orientation]]

    This  command draws error bars on all (X,Y) points (read by COLUMN X and
    Y, or specified in Array_X Array_Y) of length read by COLUMN Z or speci-
    fied  by Array_Z.  Argument may be +X X -X +Y Y or -Y.  Symmetric error-
    bars are drawn if you do not specify the sign, while only  the  errorbar
    of  the given sign is drawn if you do so. This allows independent error-
    bars in opposite directions. The size of the line at the end of the  er-
    rorbar is the Marker size and can therefore be adjusted with SET MARKER.

    Errorbars with arbitrary orientation can be obtained by specifying  code
    +O,  O  or  -O.  The orientation (in degrees) is then either read from a
    fourth array if one is specified on the command line, or otherwise taken
    from the current marker orientation (as specified in SET ORIENTATION).