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Highlights from
INTSOLVER: An interval based solver for Global Optimization

from INTSOLVER: An interval based solver for Global Optimization by Tiago Montanher
Interval based functions to solve small global optimization problems with guaranteed bounds.

evtrigonometric(x)
function y = evtrigonometric(x)

% Name: Trigonometric
% Reference: 
% Testing Unconstrained Optimization. Moré J. J., Garbow B. S., Hillstrom
% K. E., 1981. ACM Trans. Math. Software, 136 - 140.
% Variables: n
% Initial Point/ Initial Interval: [1/n,..., 1/n] /([0, 1],...,[0, 1])
% Matlab Code by Tiago Montanher (Mar. 06, 2009).

 n = length(x);
 s = sum(cos(x));
 
 for j = 1: n
   yy(j) = n - s + j*(1 - cos(x(j))) - sin(x(j));
 end
 
 y = yy;
end

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