Cross-in-tray

Problem definition

Objective function
f = @(x) -0.0001*(abs(sin(x(:,1)).*sin(x(:,2)).*exp(abs(100 - (x(:,1).^2 + x(:,2).^2).^0.5/pi))) + 1).^0.1
Optimization settings
o = struct	

% initializing struct

o.lb = -3

% lower bounds

o.ub = 3

% upper bounds

Graphic representation
[x,y] = meshgrid(o.lb:0.25:o.ub)
surf(x,y,f([x(:),y(:)]))

Problem properties

convexity smoothness minimum
0 f(-1.3494, -1.3494) = -2.06261

Optimization example with fminsearch

Optimization
rng(0)	

% for tractability

x0 = [0.5,-2]

% initial guess

[xmin,fmin,info] = fminsearch(f,x0,o)

% running minimization

Animation
rng(0)
x0 = [0.5,-2]
[~,~,info] = fminsearch(f,x0,o)
info.sol = [-1.3494 -1.3494 -2.06261]	

% solution

info.animate = true

% plot animation

info.animfreq = 5

% frame frequency

info.np = 40

% number of points for meshgrid

optimview('fminsearch',info)

References

[1] S. K. Mishra, "Global Optimization By Differential Evolution and Particle Swarm Methods: Evaluation On Some Benchmark Functions", Munich Research Papers in Economics

Related functions

fminsearch | meshgrid | surf