ZDT4 Function
Builds and returns the two-objective ZDT4 test problem. For m m m objective it is defined as follows [REMOVE_ME]f ( x ) = ( f 1 ( x 1 ) , f 2 ( x ) ) [ R E M O V E M E 2 ] f(\mathbf{x}) = \left(f_1(\mathbf{x}_1), f_2(\mathbf{x})\right) [REMOVE_ME_2] f ( x ) = ( f 1 ( x 1 ) , f 2 ( x ) ) [ REMO V E M E 2 ]
with [REMOVE_ME]f 1 ( x 1 ) = x 1 , f 2 ( x ) = g ( x ) h ( f 1 ( x 1 ) , g ( x ) ) [ R E M O V E M E 2 ] f_1(\mathbf{x}_1) = \mathbf{x}_1, f_2(\mathbf{x}) = g(\mathbf{x}) h(f_1(\mathbf{x}_1), g(\mathbf{x})) [REMOVE_ME_2] f 1 ( x 1 ) = x 1 , f 2 ( x ) = g ( x ) h ( f 1 ( x 1 ) , g ( x )) [ REMO V E M E 2 ]
where [REMOVE_ME]g ( x ) = 1 + 10 ( m − 1 ) + ∑ i = 2 m ( x i 2 − 10 cos ( 4 π x i ) ) , h ( f 1 , g ) = 1 − f 1 ( x ) g ( x ) [ R E M O V E M E 2 ] g(\mathbf{x}) = 1 + 10 (m - 1) + \sum_{i = 2}^{m} (\mathbf{x}_i^2 - 10\cos(4\pi\mathbf{x}_i)), h(f_1, g) = 1 - \sqrt{\frac{f_1(\mathbf{x})}{g(\mathbf{x})}} [REMOVE_ME_2] g ( x ) = 1 + 10 ( m − 1 ) + ∑ i = 2 m ( x i 2 − 10 cos ( 4 π x i )) , h ( f 1 , g ) = 1 − g ( x ) f 1 ( x ) [ REMO V E M E 2 ]
and x i ∈ [ 0 , 1 ] , i = 1 , … , m \mathbf{x}_i \in [0,1], i = 1, \ldots, m x i ∈ [ 0 , 1 ] , i = 1 , … , m . This function has many Pareto-optimal fronts and is thus suited to test the algorithms ability to tackle multimodal problems.
makeZDT4Function ( dimensions )
Arguments
Returns
[smoof_multi_objective_function
]
Description
Builds and returns the two-objective ZDT4 test problem. For m m m objective it is defined as follows
f ( x ) = ( f 1 ( x 1 ) , f 2 ( x ) ) f(\mathbf{x}) = \left(f_1(\mathbf{x}_1), f_2(\mathbf{x})\right) f ( x ) = ( f 1 ( x 1 ) , f 2 ( x ) )
with
f 1 ( x 1 ) = x 1 , f 2 ( x ) = g ( x ) h ( f 1 ( x 1 ) , g ( x ) ) f_1(\mathbf{x}_1) = \mathbf{x}_1, f_2(\mathbf{x}) = g(\mathbf{x}) h(f_1(\mathbf{x}_1), g(\mathbf{x})) f 1 ( x 1 ) = x 1 , f 2 ( x ) = g ( x ) h ( f 1 ( x 1 ) , g ( x ))
where
g ( x ) = 1 + 10 ( m − 1 ) + ∑ i = 2 m ( x i 2 − 10 cos ( 4 π x i ) ) , h ( f 1 , g ) = 1 − f 1 ( x ) g ( x ) g(\mathbf{x}) = 1 + 10 (m - 1) + \sum_{i = 2}^{m} (\mathbf{x}_i^2 - 10\cos(4\pi\mathbf{x}_i)), h(f_1, g) = 1 - \sqrt{\frac{f_1(\mathbf{x})}{g(\mathbf{x})}} g ( x ) = 1 + 10 ( m − 1 ) + i = 2 ∑ m ( x i 2 − 10 cos ( 4 π x i )) , h ( f 1 , g ) = 1 − g ( x ) f 1 ( x )
and x i ∈ [ 0 , 1 ] , i = 1 , … , m \mathbf{x}_i \in [0,1], i = 1, \ldots, m x i ∈ [ 0 , 1 ] , i = 1 , … , m . This function has many Pareto-optimal fronts and is thus suited to test the algorithms ability to tackle multimodal problems.
References
E. Zitzler, K. Deb, and L. Thiele. Comparison of Multiobjective Evolutionary Algorithms: Empirical Results. Evolutionary Computation, 8(2):173-195, 2000