Numeric Codes For libplot Dot Styles
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  1. dot
  2. plus (+)
  3. asterisk (*)
  4. circle
  5. cross
  6. square
  7. triangle
  8. diamond
  9. star
 10. inverted triangle
 11. starburst
 12. fancy plus
 13. fancy cross
 14. fancy square
 15. fancy diamond
 16. filled circle
 17. filled square
 18. filled triangle
 19. filled diamond
 20. filled inverted triangle
 21. filled fancy square
 22. filled fancy diamond
 23. half filled circle
 24. half filled square
 25. half filled triangle
 26. half filled diamond
 27. half filled inverted triangle
 28. half filled fancy square
 29. half filled fancy diamond
 30. octagon
 31. filled octagon

Note:
The interpretation of marker symbols 1 through 5 is the same as in the
well known Graphical Kernel System (GKS).
   By convention, symbols 32 and up are interpreted as characters in a
certain text font.  For `libplot', this is simply the current font.
