Amos source code of drawing ellipse. klick mouse on the screen to mark
5 points. Programs will draw two dimensional function with zero value
getting through marked points. programs draws gradient lines, equipotential
lines and stream lines of a function.

Program drawing ellipse with numeric method requires moving points with mouse
to refresh the plot.

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[generic]                 3062   16624  18.4% -lh5- db83 Feb 11  1980 ellipse gradient.amos
[generic]                 3147   16832  18.7% -lh5- 8a46 Feb 11  1980 ellipse numeric.amos
[generic]                 3055   16656  18.3% -lh5- 90cf Feb 11  1980 ellipse round.amos
[generic]                 3022   16550  18.3% -lh5- 6dd9 Feb 11  1980 ellipse slider.amos
[generic]                 2728   15468  17.6% -lh5- 7eba Feb 11  1980 ellipse.amos
[generic]                  334     573  58.3% -lh5- 527d Feb 11  1980 ellipse.readme
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         6 files   15348   82703  18.6%            Feb 11 03:32