Optimz

When this button is selected, the tour is following the gradient of the
projection pursuit index to find more interesting 2-dimensional views
of the data. In this mode it is usual to keep control of the "jump
size" scrollbar to alter the frequency at which derivatives are
calculated, and thus control the optimization of the projection pursuit
index.

When the guided tour obtains a maximum, it may turn itself off. It does
this when the derivatives are all within a tolerance level of zero,
meaning a better new direction cannot be found. To turn the tour back
on you need to turn "Optimz" off.

When this button is not selected, the projection pursuit index is still
being plotted, but the guided tour is not taking place.  Instead the
viewer is watching a grand tour, with new directions of rotation being
chosen at random.
