    PLOT(VI)                     3/10/75                     PLOT(VI)

    NAME
         plot: tek, gsip, vt0 - graphics filters

    SYNOPSIS
         source tek
         source gsip
         source vt0

    DESCRIPTION
         These  commands  produce  graphical  output on the Tektronix
         4014 terminal, the GSI or other Diablo-mechanism  terminals,
         and  the  on-line storage scope respectively.  They read the
         standard input to obtain plotting  instructions,  which  are
         usually  generated by a program calling the graphics subrou-
         tines described in plot(VII).  Each instruction consists of
         an  ASCII  letter usually followed by binary information.  A
         plotting coordinate is transmitted as four bytes  represent-
         ing the x and y values; each value is a signed number trans-
         mitted low-order byte first.  The assumed plotting space  is
         set by request.  The instructions are taken from

         m  move:  the  next  four bytes specify the coordinates of a
            point to move to.  This is used before writing a label.

         p  point: the next four bytes  specify  the  coordinates  at
            which a point is drawn.

         l  line:  the next eight bytes are taken as two pairs of co-
            ordinates specifying the endpoints of a line to be drawn.

         t  label:  the  bytes  up to a new-line are written as ASCII
            starting at the last point drawn or moved to.

         a  arc: the first four bytes specify the  center,  the  next
            four specify the starting point, and the last four speci-
            fy the end point of a circular arc.  The  least  signifi-
            cant  coordinate  of the end point is used only to deter-
            mine the quadrant.  The arc is  drawn  counter-clockwise.
            This  command  is  not necessarily implemented on all (or
            even any) of the output devices.

         c  circle: The first four bytes specify the  center  of  the
            circle, the next two the radius.

         e  erases the screen

         f  linemod:  takes  the following string as the type for all
            future lines.  The types are  `dotted,'  `solid,'  `long-
            dashed,'  `shortdashed,'  and `dotdashed.'  This instruc-
            tion is effective only with the Tektronix terminal.

         d  dotline: takes the first four bytes as the coordinates of
            the  beginning  of  a  dotted  line.   The next two are a
            signed x-increment, and the next two are  a  word  count.
            Following  are  the indicated number of byte-pairs repre-

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    PLOT(VI)                     3/10/75                     PLOT(VI)

            senting words.  For each bit in  this  list  of  words  a
            point  is plotted which is visible if the bit is `1,' in-
            visible if not.  Each point is offset rightward by the x-
            increment.   The instruction is effective only on the vt0
            scope.

    SEE ALSO
         plot(VII), graph(VI)

    BUGS

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