Test functions


The Rana function is a non-separable, highly multimodal function. The left figure shows the two dimensional landscape of the non-rotated version. The best solutions are at the corners. Applying a simple parameter shift makes this function non-symmetric. The right figure shows the rotated version. back


Like the Rana function, F101 is a non-separable and highly multimodal. The left figure shows the two dimensional non-rotated landscape. The right landscape has been rotated 20 degrees. back


The schwefel function is symmetric, separable and multimodal (left). Rotating this function creates a non-separable surface with similar features (Salomon 1996). back


Rosenbrock's function is symmetric, unimodal and non-separable. The long narrow ridge makes this problem difficult for some algorithms. Rotation makes this problem easier for most algorithms. back

Static Corrections

There are many difficult optimization problems in geophysics. One such problem is the ``static corrections'' problem, where seismic reflection surveys are used to construct subsurface images of geologic strata.
We introduce a synthetic static correction problem as a test function. The figure below shows a single trial of CHC on this problem. Notice that the target profile is not actually the optimal solution. back