ation, and the efficiency index 1.66.
For higher values of `k`, the efficiency index approaches
the kth root of ``(3k-2)``, hence ``k=1`` or ``k=2`` are
usually appropriate.

References
----------
.. [APS1995]
   Alefeld, G. E. and Potra, F. A. and Shi, Yixun,
   *Algorithm 748: Enclosing Zeros of Continuous Functions*,
   ACM Trans. Math. Softw. Volume 221(1995)
   doi = {10.1145/210089.210111}

Examples
--------
>>> def f(x):
...     return (x**3 - 1)  # only one real root at x = 1

>>> from scipy import optimize
>>> root, results = optimize.toms748(f, 0, 2, full_output=True)
>>> root
1.0
>>> results
      converged: True
           flag: converged
 function_calls: 11
     iterations: 5
           root: 1.0
         method: toms748
r