Dymos

July 22, 2021

This is version 1.1.0 of Dymos.
The release provides compatibility with OpenMDAO >=3.10.0, updates the
documentation to JupyterBook, and adds a few new features.

Backwards Incompatible API Changes & Deprecations

* Removed vectorize_derivs option from phase objectives due to OpenMDAO update. [605](https://github.com/OpenMDAO/dymos/pull/605)
* The dynamic argument on add_parameter has been removed. A new argument static_target has been added which has opposite meaning of dynamic. [591](https://github.com/OpenMDAO/dymos/pull/591)
* Updated phase.interpolate to automatically detect variable type, renamed to phase.interp. Old version is deprecated. [592](https://github.com/OpenMDAO/dymos/pull/592)

Enhancements

* Documentation updated to JupyterBook. [611](https://github.com/OpenMDAO/dymos/pull/611) [#613](https://github.com/OpenMDAO/dymos/pull/613) [#614](https://github.com/OpenMDAO/dymos/pull/614) [#615](https://github.com/OpenMDAO/dymos/pull/615) [#616](https://github.com/OpenMDAO/dymos/pull/616) [#618](https://github.com/OpenMDAO/dymos/pull/618)
* simulate_options are now stored within each Phase. [610](https://github.com/OpenMDAO/dymos/pull/610)
* Removed vectorize_derivs option from phase objectives due to OpenMDAO update. [605](https://github.com/OpenMDAO/dymos/pull/605)
* Updated dymos to handle the new OpenMDAO distributed I/O approach [597](https://github.com/OpenMDAO/dymos/pull/597)
* The dynamic argument on add_parameter has been removed. A new argument static_target has been added which has opposite meaning of dynamic. [591](https://github.com/OpenMDAO/dymos/pull/591)
* Updated phase.interpolate to automatically detect variable type, renamed to phase.interp. Old version is deprecated. [592](https://github.com/OpenMDAO/dymos/pull/592)

Bug Fixes

* Fixed an issue with units in linkage constraints. [620](https://github.com/OpenMDAO/dymos/pull/620)
* Fix for key error when performing order reduction under hp adaptive refinement. [590](https://github.com/OpenMDAO/dymos/pull/590)
* Parameters in the ODE system now respect both dynamic=True and False. [581](https://github.com/OpenMDAO/dymos/pull/581)

Miscellaneous

* Added missing example Brachistochrone with upstream initial and duration states. [623](https://github.com/OpenMDAO/dymos/pull/623)
* Added require_pyoptsparse to all tests that use pyOptSparseDriver [624](https://github.com/OpenMDAO/dymos/pull/624)
* Added a couple of fixes to examples docs [622](https://github.com/OpenMDAO/dymos/pull/622)
* Fixed some typos in 'Getting Started' section of the docs [621](https://github.com/OpenMDAO/dymos/pull/621)
* Install coveralls from pypi in github workflow [601](https://github.com/OpenMDAO/dymos/pull/601)
* Change base_dir arg to coveralls [600](https://github.com/OpenMDAO/dymos/pull/600)
* Fixed minor typos in docs. [599](https://github.com/OpenMDAO/dymos/pull/599)
* Removed require_pyoptsparse and moved it to OpenMDAO. [595](https://github.com/OpenMDAO/dymos/pull/595)
* Added publishing mkdocs to gh-pages. [594](https://github.com/OpenMDAO/dymos/pull/594)
* Added github actions workflow for CI. [589](https://github.com/OpenMDAO/dymos/pull/589)
* Readme updated to point to JOSS paper. [578](https://github.com/OpenMDAO/dymos/pull/578)
* Updated JOSS bibliography. [573](https://github.com/OpenMDAO/dymos/pull/573) [#574](https://github.com/OpenMDAO/dymos/pull/574) [#576](https://github.com/OpenMDAO/dymos/pull/576) [#577](https://github.com/OpenMDAO/dymos/pull/577)
* Fixed some references in JOSS paper. [572](https://github.com/OpenMDAO/dymos/pull/572)
* Minor grammar and consistency edits for JOSS paper. [571](https://github.com/OpenMDAO/dymos/pull/571)

March 25, 2021

This is version 1.0.0 of Dymos.
This release primarily removes some deprecated experimental features, along with implementing a few bug fixes.

Backwards Incompatible API Changes & Deprecations

* The RungeKutta Transcription is removed. [550](https://github.com/OpenMDAO/dymos/pull/550)
* Two-character location specifiers ('++', '--', '+-', '-+') are removed in favor of 'initial' and 'final' [556](https://github.com/OpenMDAO/dymos/pull/556)
* User must now specify `solve_segments='forward'` or `solve_segments='backward'` when using solve_segments capability (True is no longer valid). [557](https://github.com/OpenMDAO/dymos/pull/557)
* `add_input_parameter` and `add_design_parameter` dropped in favor of `add_parameter`. [558](https://github.com/OpenMDAO/dymos/pull/558) [#561](https://github.com/OpenMDAO/dymos/pull/561)
* Removed the deprecated command line interface due to it being a somewhat hackish abuse of OpenMDAO's hooks. [563](https://github.com/OpenMDAO/dymos/pull/563)
* Removed the deprecated 'disc' node subset in favor of the more correct 'state_disc' [565](https://github.com/OpenMDAO/dymos/pull/565)
* Removed the deprecated 'custom_targets' option for parameters.' [565](https://github.com/OpenMDAO/dymos/pull/565)

Enhancements

* User will now be warned when multiple timeseries outputs were attempted with the same name. [567](https://github.com/OpenMDAO/dymos/pull/567)

Bug Fixes

* The `ode_class` option of phase is now marked non-recordable. [555](https://github.com/OpenMDAO/dymos/pull/555)
* Fixed doc building due to a change in OpenMDAO. [564](https://github.com/OpenMDAO/dymos/pull/564)

Miscellaneous

* Modified examples to use the preferred `fix_initial=True` for time and states instead of "pinched bounds", e.g. `initial_bounds=(0, 0)`. [560](https://github.com/OpenMDAO/dymos/pull/560)

February 18, 2021

This release of Dymos adds several examples demonstrating various capabilities of the code.
Per user request, the ODE of a system can now be provided via a callable function that
takes `num_nodes` and any other potential initialization keywod arguments.
This allows OpenMDAO's ExecComp to be used as an ODE if wrapped in a lambda, for instance.

Some bugs were fixed as part of introducing these examples. For instance, default values for
states and times were being ignored - this is now fixed. In addition, Trajectory parameters
are now saved to the simulation database file.

This is expected to be the final release of Dymos before v1.0.0, when several existing
deprecated features will be removed from the code.

Backwards Incompatible API Changes & Deprecations

None

Enhancements

* Added the racecar example from pwmdebuck, demonstrating cycling constraints and integration about arclength instead of time. [535](https://github.com/OpenMDAO/dymos/pull/535)
* Simplified the SSTO example to use a single ODE component with complex-step. [534](https://github.com/OpenMDAO/dymos/pull/534)
* Added a balanced field length example. [533](https://github.com/OpenMDAO/dymos/pull/533)
* Added the ability to use a callable that returns a System as an ODE. [528](https://github.com/OpenMDAO/dymos/pull/528)

Bug Fixes

* Removed duplication of inputs to timeseries when multiple outputs may use the same source data. [543](https://github.com/OpenMDAO/dymos/pull/543)
* Fixed a bug where timeseries outputs of non-dynamic ODE outputs would cause an exception. [521](https://github.com/OpenMDAO/dymos/pull/521)

Miscellaneous

* Reworked the cannonball example to make it more simple [545](https://github.com/OpenMDAO/dymos/pull/545)
* Placed some more tests under the use_tempdirs decorator to clean up output. [530](https://github.com/OpenMDAO/dymos/pull/530)
* Added a test that checks all docstrings vs the NumpyDoc standard. [526](https://github.com/OpenMDAO/dymos/pull/526)
* Clean up implementation of wildcard units when adding multiple timeseries at once. [523](https://github.com/OpenMDAO/dymos/pull/523)

January 21, 2021

This release of Dymos brings a few improvements and bug fixes.

We've implemented introspection for boundary and path constraints such that units and shapes of the constrained quantities can be determined during the setup process and no longer are required to be specified.
The use of solve_segments to have a solver converge the dynamics and thus provide a shooting method at the optimizer has been improved. Option solve_segments can now take on values 'forward' or 'backward' to provide forward or backward shooting.
Linkage constraints will now result in an error if the quantity on each side of the linkage is governed by the optimizer (is a design variable) but is fixed in value (not allowed to be varied).

Backwards Incompatible API Changes & Deprecations

* The command line interface is deprecated due to inconsistent behavior. [505](https://github.com/OpenMDAO/dymos/pull/505)

Enhancements

* Changed CoerceDesvar to handle vector values for ref/ref0/scaler/adder. Carried over changes to for defect ref/defect scaler. [464](https://github.com/OpenMDAO/dymos/pull/464)
* Changed solve_segments to allow it to be used when neither fix_initial nor fix_final are True. [490](https://github.com/OpenMDAO/dymos/pull/490)
* Added detection of unsatisfiable linkage constraints (where quantities on both sides cannot be changed by the optimizer). [502](https://github.com/OpenMDAO/dymos/pull/502)
* Added introspection for boundary and path constraints. [506](https://github.com/OpenMDAO/dymos/pull/506)

Bug Fixes

* Fixed a bug with using grid refinement if one or more of the states are vector-valued. [492](https://github.com/OpenMDAO/dymos/pull/492)
* Fixed issue where show_plots argument to run_problem is permanently changing matplotlib backend. [497](https://github.com/OpenMDAO/dymos/pull/497)
* Fixed a bug where trajectory.simulate() would crash if trajectory were not named the common 'traj' name. [500](https://github.com/OpenMDAO/dymos/pull/500)
* Fixed a bug that prevented restart from working with multiphase trajectories, and now include static parameters in the solution file. [510](https://github.com/OpenMDAO/dymos/pull/510)
* Fixed a bug associated with polynomial control rate sources, and added coverage of more cases. [513](https://github.com/OpenMDAO/dymos/pull/513)
* Fixed exception when simulating a trajectory with a parameter for which None was declared as the target for one of its phases. [515](https://github.com/OpenMDAO/dymos/pull/515)

Miscellaneous

None

December 14, 2020

This release of Dymos adds a few important features:
- Dymos can now automatically generate plots of all timeseries outputs
- State rates may now be tagged in the ODE

There are also several bug fixes.

Backwards Incompatible API Changes & Deprecations

* None

Enhancements

* Dymos can now automatically generate plots of all timeseries outputs. [469](https://github.com/OpenMDAO/dymos/pull/469)
* States can now be discovered automatically by tagging their rate variables in the ODE. [477](https://github.com/OpenMDAO/dymos/pull/477) [#481](https://github.com/OpenMDAO/dymos/pull/481) [#484](https://github.com/OpenMDAO/dymos/pull/484)

Bug Fixes

* Fixed issue where polynomial controls were not able to be linked across phases. [462](https://github.com/OpenMDAO/dymos/pull/462)
* Fixed a bug that was preventing parameters from being state rate sources. [466](https://github.com/OpenMDAO/dymos/pull/466)
* Users may now specify parameter shapes as integers or iterables other than tuples. [467](https://github.com/OpenMDAO/dymos/pull/467)

Miscellaneous

* Fix for apache license string in setup.py classifiers since it was not recognized by PyPI. [458](https://github.com/OpenMDAO/dymos/pull/458)
* Added a long description for PyPI. [460](https://github.com/OpenMDAO/dymos/pull/460)
* Some documentation cleanup for the JOSS review [474](https://github.com/OpenMDAO/dymos/pull/474) [#488](https://github.com/OpenMDAO/dymos/pull/488)
* Dropped the dependency on the parameterized package with the intent to utilize subTest in the future. [479](https://github.com/OpenMDAO/dymos/pull/479)

November 16, 2020

This release of Dymos fixes an issue that now allows portions of an array
output to be connected to a parameter.

This version works with OpenMDAO 3.3.0 but version 3.4.1 offers some
improved handling of parameters.

Backwards Incompatible API Changes & Deprecations

* Parameter shapes in 0.16.1 were stored as (1,) + the shape of the parameter. Now they are shaped as expected. [444](https://github.com/OpenMDAO/dymos/pull/444)

Enhancements

* State shapes and units, if not explicitly given, are now pulled from targets (if present and uniquely defined), or from the rate source variable. [449](https://github.com/OpenMDAO/dymos/pull/449)

Bug Fixes

* Fixes a bug where user-defined shapes of states were colliding with those found during introspection, and other state introspection updates. [449](https://github.com/OpenMDAO/dymos/pull/449)

* Fixes a bug that prevented the use of numpy arrays as a boundary constraints [450](https://github.com/OpenMDAO/dymos/pull/450)

Miscellaneous

* Added test to verify functionality of OpenMDAO 3.4.1 that allows the final value of a control (or a partial portion of any output) to be connected to a parameter. [445](https://github.com/OpenMDAO/dymos/pull/445)