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Environmental Modeling Community of Practice

PEST Release Notes

Version: 6.05

Corrections & Improvements to Prior Versions

  • Parameter "upgrade vector bending" and "parameter bounds gluing" added to PEST to increase optimization efficiency.
  • Expanded file importation capabilities for TSPROC.
  • Significant additions to TSPROC including detailed flow comparison statistics and digital high/low/bandpass and baseflow separation filtering.
  • Release of PEST v6.0 with the addition of "Automatic User Intervention" (AUI) for vastly improved performance in difficult inversion contexts.
  • Introduction of two new PEST Utilities PARAMFIX and WTFACTOR to enhance regularization functionality.

Version: 5.5

Corrections & Improvements to Prior Versions

  • First released through CEAM on January 11, 2002.
  • Added new regularization functionality useful for the parameterization of heterogeneous two- and three-dimensional spatial model domains.
  • All names pertaining to parameters, parameter groups, observations, observation groups and prior information items can now be up to twelve characters in length.
  • Prior information items must now be assigned to observation groups.
  • Uncertainties in observations and prior information equations used in the inversion process can now be expressed in terms of covariance matrices, rather than simply in terms of weights.
  • If derivatives of model outputs with respect to adjustable parameters can be calculated by the model, rather than by PEST through the use of finite differences, then PEST can use these derivatives if they are supplied to it through a file written by the model.
  • Different commands can be used to run the model for different purposes for which the model is used by PEST (viz. testing parameter upgrades, calculating derivatives with respect to different parameters, etc).
  • PEST can now send "messages" to a model, allowing the model to adjust certain aspects of its behavior depending on the purpose for which it is run by PEST.
  • PEST stores the Jacobian matrix corresponding to the best set of parameters achieved up to any stage of the parameter estimation process in a special binary file which is updated as the parameter estimation process proceeds. A new utility program named READJAC re-writes the Jacobian matrix in text format for user-inspection.
  • PEST prints out a more comprehensive suite of information on composite parameter sensitivities than was available in previous versions.
  • A new utility named PAR2PAR has been added to the PEST suite. This is a "parameter preprocessor" which allows the user to manipulate parameters according to mathematical equations of arbitrary complexity before these parameters are supplied to the model.