Advanced Options Dialog Box |
The Advanced Options dialog box contains the following options:
Controls the method used to compute approximate first partial derivatives.
Choose "Forward" to look for results in one direction from the current point.
Choose "Central" to look for results in two opposing directions from the current point. This can take more time, but may yield better results with fewer total iterations.
Controls the method used to estimate initial values at the beginning of each search.
Choose "Tangent" to extrapolate from the line tangent to the reduced objective function.
Choose "Quadratic" to extrapolate to the minimum or maximum of a quadratic function fitted to the reduced objective function at its current point.
Saves time by recognizing whether all the unknown variables occur linearly in all the constraints and assumes that first partial derivatives with respect to these variables are constant.
Use this option only if you know that nonlinearly occurring variables do not appear to change linearly.
Makes the nonlinear solver attempt to find a global maximum or minimum within the feasible region, rather than merely a local one.
Finds good, though not necessarily optimal, solutions for problems where "classical" gradient methods are not sufficient. "Classical" gradient methods assume that the problem functions (objective and constraints) are smooth functions of the variables (that is, the gradients of these functions are everywhere continuous); the ability to converge to a local optimum depends on this assumption. In problems with non-smooth or even discontinuous functions, these methods often have difficulty reaching a solution. In such problems, the Evolutionary option, which makes no assumptions about the problem functions, can often help you find a good solution.
Even in smooth nonlinear problems, the "classical" gradient methods only find a locally optimal solution, and may miss a better solution far from the starting point you provide. The Evolutionary option gives you a much better chance of finding the globally optimal solution in such problems.
These advanced options apply to the Conjugate Gradient or Quasi-Newton methods.
These options are for advanced users. You should use these only if a solution wasn't found using the default options or if you want tight control over the solving method.