Version 5.3.1 (2013/05/15)
Highlights
- Efficiency / precision / stability enhancements for stochastic expansions. 
- Support for native Windows builds with MS Visual Studio 2008 and Intel fortran 11.1 (also with Windows Command Prompt via CMake’s “NMake Makefiles” build generator). 
- Bayesian calibration via QUESO now available in all Dakota distributions 
Uncertainty Quantification (UQ)
- Efficiency / precision / stability enhancements for stochastic expansions. - Stochastic collocation now employs a barycentric Lagrange formulation for global value-based interpolants in both nodal and hierarchical cases. This formulation significantly reduces run times when sampling on the interpolant. Further, tensor interpolant value/gradient computations now employ a multivariate Horner’s rule for all interpolation polynomial cases. 
- Polynomial chaos expansions also now employ Horner’s rule for all 1D polynomial evaluations and employ a multivariate Horner’s approach in selected value computations for tensor expansions. 
 
Optimization and Calibration
- Bayesian calibration via QUESO - Now available in all Dakota distributions, disabled by default. 
- Additional QUESO user controls for surrogate type and whether to calibrate sigma. 
- Progress toward building QUESO under Trilinos TriKota 
 
Framework
- Input/Output - Better use of the Boost.Filesystem library for portable interaction with the platform’s native filesystem during data exchange when using ‘fork’ and ‘system’ interfaces. 
 
- Interfaces - Improved NumPy behavior: when building Python interface, always try to link numpy, then give user option to turn enable/disable at runtime. No longer require PWD to be on the PYTHONPATH. 
- Improved test/code coverage in ‘fork’ and ‘system’ interfaces, especially those leveraging Dakota’s work_directory feature. 
 
- Build System / TPLs - Numerous patches for Microsoft Visual Studio portability: strings, signals, min/max macros, sleep, extern, reserved keywords, asynch system calls, Boost filesystem, install dependencies, dakota_test.perl. 
- Enable testing of external distributions by leaving out tests known to fail. 
- Add tests for work_directory feature. 
 
Miscellaneous Bug Fixes
- BUG: resolve testing differences from the baseline and improve reliability / RBDO performance for cases involving second-order integrations. 
- BUG: Command line options -help and -version could result in accessing invalid iterator. 

