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This is not the final release version
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= Release Notes for OpenModelica [milestone:1.9.0] Beta4 Release =
[[PageOutline(2-3)]] 
The OpenModelica 1.9.0 beta4 release has a more complete OMC model compiler. It simulates many more models than the previous 1.8.1 version and 1.9.0 beta releases. This is the first release that simulates many (58%) of the MSL 3.2.1 Fluid models. Regarding the whole MSL 3.2.1, 233 out of 253 example models now simulate (92%) compared to 118 in the beta2 release Oct 20, and 30% in the 1.9.0 beta1 release. There is also partial support for some other libraries like ThermoSysPro. It also contains a further improved ModelicaML version for the latest Eclipse and Papyrus releases.
== OpenModelica Compiler (OMC) ==
This release mainly includes bug fixes and improvements of the OpenModelica Compiler (OMC), including, but not restricted to the following:
* A more stable and complete OMC model compiler. The 1.9.0 beta4 version simulates many more models than the previous 1.8.1 version and OpenModelica 1.9.0 beta versions.
* Much better simulation support for MSL 3.2.1, now 233 out of 253 example models simulate (92%) compared to 118 in the beta2 release Oct 20, and 30% in the 1.9.0 beta1 release.
* Good support for the MSL 3.2.1 MultiBody library. All example models except one simulate using dynamic state selection, the remaining one simulates with a special flag.
* Fairly good support for the MSL 3.2.1 Fluid library, now 24 example models simulate (58%), and all flatten.
* Better simulation support for several other libraries, e.g. more than twenty examples simulate from ThermoSysPro, and all but one model from PlanarMechanics simulate.
* Improved tearing algorithm for the compiler backend. Tearing is by default used.
* Much faster matching and dynamic state selection algorithms for the compiler backend.
* New index reduction algorithm implementation.
* New default initialization method that symbolically solves the initialization problem much faster and more accurately. This is the first version that in general initialize hybrid models correctly.
* Better class loading from files. The package.order file is now respected and the file structure is more thoroughly examined (#1764).
* It is now possible to translate the error messages in the omc kernel (#1767). Swedish and German language translations available.
* Enhanced ModelicaML version with support for value bindings in requirements-driven modeling available for the latest Eclipse and Papyrus versions. GUI specific adaptations. Automated model composition workflows (used for model-based design verification against requirements) are modular and have improved in terms of performance.
* FMI for co-simulation with OMC as master, and improved FMI import.
* Checking (when possible) that variables have been assigned to before they are used in algorithmic code (#1776).
* Full version of Python scripting.
* 3D graphics visualization using the Modelica3D library.
* Prototype support for uncertainty computations, special feature enabled by special flag.
* Parallel algorithmic Modelica support (ParModelica) for efficient portable parallel algorithmic programming based on the OpenCL standard, for CPUs and GPUs.
* Support for optimization of semiLinear according to MSL 3.3 chapter 3.7.2.5 semiLinear (r12657,r12658).
* The compiler is now fully bootstrapped and can compile itself using a modest amount of heap and stack space (less than the RML-based compiler, which is still the default).
* Some old debug-flags were removed. Others were renamed. Debug flags can now be enabled by default.
* Removed old unused simulation flags noClean and storeInTemp (r15927).
* Many stack overflow issues were resolved.
== Other OpenModelica Subsystems ==
* '''''OpenModelica Notebook (OMNotebook)'''''. A `shortOutput` option has been introduced in the simulate command for less verbose output. The DrModelica interactive document has been updated and the models tested. Almost all models now simulate with OpenModelica.
* '''''OpenModelica Eclipse Plug-in (MDT).''''' Enhanced debugger for algorithmic Modelica code, supporting both standard Modelica algorithmic code called from simulation models, and MetaModelica code.
* '''''OpenModelica Development Environment (OMDev.)''''' Migration of version handling and configuration management from CodeBeamer to Trac.
* '''''Graphic Editor OMEdit:'''''
  - Options to set matching algorithm and index reduction method for simulation.
  - Backward and Forward navigation support in Documentation view.
  - Output window for simulations.
  - Preserving user customization.
  - Show dummy red box for models with no graphical annotations.

== Detailed Changes ==

[[TicketQuery(milestone=1.9.0,status=closed,severity!=trivial,resolution=fixed|-,col=changelog,group=component,format=table)]]

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