Announcing What’sBest! 18 : New Features
General:
- Improved support for SUMIF functions
- Resolved a memory issue with large Stochastic programs
“Exotic” Excel Functions Support:
- Assume Linear Option: allows use of any Excel function as long as the resulting optimization model is linear in the Adjustable cells. What’sBest! tests if this is true.
- Binary Black Box Option: allows use of any Excel function as long as all the Adjustable cells are binary and the model includes no constraints. Linearity is not required.
- Improved detection and reporting of unsupported formulae
Performance Improvements:
- Significantly better handling of “infinite” Excel ranges, where user specifies an unnecessarily large range, e.g., an entire column.
Linear and Integer Solver Improvements:
- Improved heuristics for general integer programs
- Average performance improvement of 2-3% on our standard test set
Nonlinear and Global Solver Improvements:
- Faster (order of magnitude) solution of linear fractional programs (ratio objectives)
- Improved bound tightening process in preprocessing of nonlinear models
- Auxiliary variables generated automatically to improve performance with complicated expressions
- Support for additional useful but “problematic” functions: Power utility function (x^g-1)/g and the exponential ratio function (exp(g) – 1)/g, are important in some situations modeling consumer behavior. The solver can now robustly avoid the numerical problems that would otherwise occur when g approaches 0.
Linearization Improvements:
- More expressions can be automatically linearized, so you can now use a fast linear solver where otherwise a much slower (30x?) nonlinear solver might be required.
- Advanced linearization of QP and Conic models
- Improved linearization of certain IF expressions.
