OpenMDAO 2.7.0 Released

OpenMDAO 2.7.0 has been released.

Here are the release notes listing the new features, bug fixes and a couple of backwards-incompatible changes:

New Features:

• You can now define guess_nonlinear method at the group level
• New documentation added about the N2 diagram usage
• Significant improvement to documentation search functionality (by default, only searches the feature docs and user guide now)
• Improvements to support for complex-step across a full model (specifically when guess_nonlinear is implemented)
• Derivatives:
  • Improved support for full-model complex-step when models have guess_nonlinear methods defined
  • **Experimental** FD and CS based coloring methods for partial derivative approximation. Valuable for efficiently using FD/CS on vectorized (or very sparse) components
• Solvers:
  • `Solver failed to converge` message now includes solver path name to make it more clear what failed
  • Improved pathname information in the singular matrix error from DirectSolver
  • Directsolver has an improved error message when it detects identical rows or columns in Jacobian
  • NonlinearGaussSeidel solver now accounts for residual scaling in its convergence criterion
  • New naming scheme for solver debug print files (the old scheme was making names so long it caused OSErrors)
• Components:
  • ExecComp now allows unit=<something> and shape=<something> arguments that apply to all variables in the expression
  • New AkimaSpline component with derivatives with respect to training data inputs
• Visualization
  • Several improvements for the N2 diagram for large models
  • N2 diagram html files have been reduced in size significantly
  • `openmdao view_model` command line utility now supports case record database files
  • (Experimental) Automatic XDSM generator (using either Latex with pyXDSM or html with XDSMjs)
    • contributed by Peter Onodi
    • uses XDSMjs v0.6.0 by Rémi Lafage (https://github.com/OneraHub/XDSMjs)

Backwards Incompatible API Changes:

• New APIs for total derivative coloring that are more consistent with partial derivative coloring (previous APIs are deprecated and coloring files generated with the previous API will not work)
  
• The API for providing a guess function to the BalanceComp has changed. guess_function is now passed into BalanceComp as an init argument.
  
• Changed the N2 diagram json data formatting to make the file size smaller. You can’t use older case record databases to generate an N2 diagram with latest version.
  
• The problem level `record_iteration` method was not properly respecting the includes specification
  
• All component methods related to execution now include `discrete_inputs` and `discrete_outputs` arguments when a component is defined with discrete i/o. If no discrete i/o is defined, the API remains unchanged. (includes `solve_nonlinear`, `apply_nonlinear`, `linearize`, `apply_linear`, `compute`,
  `compute_jac_vec_product`, `guess_nonlinear`)
  
• The internal Driver API has changed, a driver should execute the model with `run_solve_nonlinear` to ensure that proper scaling operations occur .
  

Bug Fixes:

• CaseRecorder was reporting incorrect values of scaled variables (analysis was correct, only case record output was wrong)
• ExecComp problem when vectorize=True, but only shape was defined.
• Incorrect memory allocation in parallel components when local size of output went to 0
• Multidimensional `src_indices` were not working correctly with assembled Jacobians
• Fixed problem with genetic algorithm not working with vector design variables
  • contributed by jennirinker
• Fixed incompatibility with mpich mpi library causing “PMPI_Allgather(945).: Buffers must not be aliased” error
  • contributed by fzhale and nbons