[racket] Controlling the size of plot symbols

> It might be time to take another look at Jens Axel's ideas for adaptive
> sampling, now that Plot can do it in 3D without b0rking it.

In a nut shell: A plotting algorithm should sample the function the
same way a numeric integration routine does. The number of samples in
a given interval should depend on how the function oscillates.

For one dimensional plotting and for references to a description of
the algorithm see:
https://github.com/soegaard/bracket/blob/master/plotting/adaptive-plotting.rkt

I have collected "horror" examples to test the plotting routine. See
the end of the file.

/Jens Axel