LINE CHARACTERISTICS - MSU CHEMISTRY VECTOR



                                T. V. Atkinson
                           Department of Chemistry
                          Michigan State University
                            East Lansing, MI 48824


                                  07-DEC-82







        1.0  INTRODUCTION


             Some graphic output devices allow the user to select  the
        type  of  line  to  be  used  in a drawing from a menu of line
        varieties.  The most  universal  choice  is  that  of  written
        (visible)   or   unwritten   (invisible)  lines.   The  actual
        implementation of any line variety may reside in the  hardware
        capabilities of the graphic devices, constructs in the driving
        software, or both.  For the graphic output  devices  currently
        supported  by the MSU Chemistry Department routine VECTOR, one
        or more of the three line characteristics, width, pattern, and
        color,  may  be  varied  independently  of  one  another.   In
        addition, of course, the selection of written/unwritten  lines
        is  provided.   The  actual  set  of the three characteristics
        available for a given device varies and is shown in Table L.1.
        Although  the  line  type  for  each  line  of a drawing could
        conceivably be different, most software implementations  group
        lines  together  into  sets which utilize the same line types.
        For example, all the lines used to construct a character  will
        usually  be  of the same type.  Or, all lines used to constuct
        the minor tick marks of an axis will  probably  be  the  same.
        Figures  L.1  through  L.3  illustrate  a partial menu of line
        types for a few of the VECTOR supported devices.

             The method of specifying which of the  legal  line  types
        are  to  be used at a given point in a drawing varies with the
        actual implementation (See MULPLT.DOC,  AXIS.DOC,  SYMPLT.DOC,
        VECTOR.DOC, and the WIZARD'S MENU).




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                                  Table L.1

          Variable Line Characteristics for VECTOR Supported Devices


                DEVICE          Variable Line Characteristics

                Tek 4010        -
                HP72xx          Color (pen selection)
                Grinell         Color
                Printronix      Width, Pattern
                Versatec        Width, Pattern
                Ramtek          Color




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                        Versatec Line Characteristics


















































                                  Figure L.1


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                       Printronix Line Characteristics


















































                                  Figure L.2


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                       Paper Tiger Line Characteristics


















































                                  Figure L.3