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Version 6.3 - May 2014

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New functionality

Random Numbers & Sampling

A new pseudorandom number generator using the SIMD implementation of the Mersenne Twister by Mutsuo Saito and Makoto Matsumoto. This affects backward compatibility of models with stochastic elements. See NOISE RNG for information about generators and backward compatibility.

Optimization and sensitivity control files may now specify a random seed of 0 to trigger randomization to system cryptographic sources (useful for performing independent runs on multiple computers without editing the control files). See Optimization Control and Sensitivity Control.

Improved sampling for Sensitivity (Monte Carlo) Simulations.



Improvements to many algorithm details for MCMC/SA

oImproved parameter defaults

oBetter numerical stability of chain statistics and the PSRF diagnostic

oA more robust proposal distribution, yielding better acceptance rates

oBetter outlier handling

oReduced memory requirements

A broader distribution of initial test points in random multistart optimization (MWYS).

Improved speed in stochastic optimization, with support for the File sensitivity control option.



Improvements to the 64 bit version of Vensim DSS/Pro for Microsoft Windows. This should be considered a beta version, any problems please report immediately to or in the forum topic devoted to the release.

Minor changes to port the 64 bit version to the multicontext DLL and Linux/Mac shared library for servers.

The 'View->Show Hidden" level is now sketch-specific. It persists when a model is saved in binary (.vmf) format, but gets reset to 0 (None) when a .mdl format model is opened.

Improvements to the vensim_get_state function in the DLL/shared library


Bug Fixes

Further improvements to the rounding algorithm for Pretty number formatting.

Missing Mac workbench variable in the title bar has been moved to the status bar.

Problem loading files embedded in packages (vpm) in the multicontext (server) dll has been resolved.

Concurrency problem when reading models with macros fixed.

Improved user abort behavior for optimizations.

Fix for GET DIRECT SUBSCRIPTS with text files.

MENU>RUN dataset loading position fixed.

Fixed issue with dataset export using |.

Improved handling of paths with "." in directory names.

Patterned lines on custom graphs respond to line width.