Best Formatter 

Purpose: for a group of numbers, select a formatter that correctly and 
  efficiently represents each number of the set.

Cases:
   1. linearly spaced.  
   2. logarithmically spaced.
   3. arbitary set of similar magnitude
   4. arbitary set of differing magnitudes
   3a. similar, large magnitude
   3b. similar, order-one magnitude

Is (1) an instance of (3), and (2) an instance of (4)?

Case 3b solution:
   Find the greatest common divisor of the numbers, and let this
set the number of fractional decimal places.  

Case 3a solution:
   Identify the base exponent to make each number order one, specifically
so the mantissas of the numbers vary from 1-100.  Then use gcd to determine
number of digimal places, and express each number with the common exponent
pulled out.

Case 4 solution:
???



Case 3 examples:
dv= DatumVector.newDatumVector( new double[] { 100000, 125000, 105000 }, Units.dimensionless );

Case 4 examples:
dv= DatumVector.newDatumVector( new double[] { 0.002, 2.001, 105.001 }, Units.dimensionless );
dv= DatumVector.newDatumVector( new double[] { 1e3, 1e6, 1e9, 2.345e7 }, Units.dimensionless );
dv= DatumVector.newDatumVector( new double[] { 0.001, 1.0, 1000.00 }, Units.dimensionless );