fully.
         Current function value: 0.000000
         Iterations: 17
         Function evaluations: 34
>>> minimum[0]
-8.8817841970012523e-16

References
----------
.. [1] Nelder, J.A. and Mead, R. (1965), "A simplex method for function
       minimization", The Computer Journal, 7, pp. 308-313

.. [2] Wright, M.H. (1996), "Direct Search Methods: Once Scorned, Now
       Respectable", in Numerical Analysis 1995, Proceedings of the
       1995 Dundee Biennial Conference in Numerical Analysis, D.F.
       Griffiths and G.A. Watson (Eds.), Addison Wesley Longman,
       Harlow, UK, pp. 191-208.

)