This attribute controls the appearance of an annotated
coordinate grid (drawn with the astGridastGrid function) by determining
the length of the minor tick marks drawn on the axes of a PlotPlot.
It takes a separate value for each physical axis of the Plot so
that, for instance, the setting "MinTickLen(2)=0" specifies the
length of the minor tick marks drawn on the second axis.
The MinTickLen value should be given as a fraction of the
minimum dimension of the plotting area. Negative values cause
minor tick marks to be placed on the outside of the
corresponding grid line or axis (but subject to any clipping
imposed by the underlying graphics system), while positive
values cause them to be placed on the inside.
The default value is
0.007.