Release Notes for OpenModelica 1.21.0 — OpenModelica User's Guide v1.22.0-dev-76-g26b9177494 documentation

# Release Notes for OpenModelica 1.21.0

The 1.21.0 release of OpenModelica doesn't contain any major new feature, but it contains many improvements and bugfixes that significantly improved the quality of the software with respect to the previous 1.20.0 release.

The new single-step gbode solver has been further developed and can now be used as a serious alternative to the more established dassl, ida, and cvode solvers. A full-fledged GUI for its configuration is still not available and will be added in future versions. Currently, the method defaults to esdirk4, a general-purpose 4-th order implicit method. Other methods can be set with the -gbm simulation flag, and each method now automatically selects the best advanced options. All solvers use variable step-size with error control by default, but they can be turned to fixed time step by adding the -gbctrl=const simulation flag.

A completely overhauled architecture for the interaction between the OMEdit GUI and the underlying OMC compiler is now experimentally available in 1.21.0. It relies on the new frontend to instantiate the classes being edited, rather than trying to re-do it from scratch on the GUI side. This architecture provides faster user interaction and allowed to fix many shortcomings of the GUI, e.g. lack of proper support for replaceable classes with parameters, conditional connectors and parameter dialog activation depending on parameters, etc.

## OpenModelica Compiler (OMC)

The new front end has been further improved with about 20 bug fixes, here is a complete list. Major development work went into supporting the development and fine-tuning a new API for the the OMEdit GUI, see tickets.

Several fixes were made to the current backend, although development work is now mostly focused on the new backend, which includes array-preserving code generation features. The new backend is still not capable of running most models from mainstream libraries. However, it is starting to show interesting results on selected large-scale test models, with size up to a million equations. These models can now be handled with reasonable amounts of time required to build and compile the simulation code. The new backend can be activated with the `--newBackend` compiler flag.

Several bug fixes were made to the code generation process. The new CMake-based build infrastructure has been further developed and is now nearly complete, including support for FMI generation.

Many bug fixes and improvements were made to the C runtime, mostly regarding the new gbode solver. This solver is fast reaching production quality and can now be used as a serious alternative to the mainstream dassl, ida, and cvode solvers; it also replaces deprecated obsolete solvers such as impeuler, trapezoid, imprungekutta, etc., that will be removed in future versions.

## Graphical Editor OMEdit

About 60 issues were successfully addressed in the OMEdit graphical editor. Most notably, the performance of the GUI support for replaceable classes has been improved dramatically; therefore that option, which is required to use Modelica.Media and Modelica.Fluid, is no longer optional but always active by default.

About half of the addressed issues concern the development and fine tuning of the new instance-based interface, that is going to be much faster than the existing one and to address long-standing issues such as supporting conditional connectors and replaceable classes with parameter modifiers.

This new interface can be activated with the Tools | Options | General | Enable instance API option. It is mostly in place now, but it still requires further testing and debugging before it can replace the existing one for good. If you want to experiment with it, we suggest you to use the latest 1.22.0-dev nightly build version, that incorporates the latest developments and bug fixes. Please try that one before reporting issues on the bug tracker.

## Scripting interfaces

The OMMatlab interface was significantly improved in this version, see tickets. In particular, it is now possible to linearize a system in many different conditions without recompiling it each time, which is useful model-based control design.

## List of tickets closed in 1.21.0

List of closed tickets in 1.21.0. Over 130 issues were resolved.

## Next releases

The next release 1.22.0 is planned to be release in Q4 2023. It will include the new instance-based editing in OMEdit, featuring support of conditional connectors, parameter-depending dialog annotation, hierarchical editing of models, and faster rendering of complex diagrams.

Download it from: https://openmodelica.org

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.20.0...v1.21.0

# Release Notes for OpenModelica 1.20.0

The first most notable feature of this release is the automatic installation of the Modelica Standard Library (MSL), which is now fully integrated with the Package Manager. Every time any tool of the OpenModelica suite (e.g. OMEdit, OMNotebook, OMShell, etc.) attempts to load a version of the MSL, it checks if it has already been installed in the user's set of system libraries, which is handled by the Package Manager and is located in the user's .openmodelica directory. If that directory is empty, either because of a fresh install, or because it has been deleted, then the MSL is automatically installed in the user's system libraries from cached zip files in the OpenModelica installation directory; in fact, both MSL 3.2.3 (which is backwards compatible with 3.2.2 and 3.2.1) and 4.0.0 are installed, so that any library created during the last ten years can run out of the box.

This automatic installation does not require any Internet connection, so it also works behind corporate firewalls or in situations with limited available bandwidth. This solution uses the same package manager that is also used to install other system libraries, contrary to the solution implemented in versions 1.18.0 and 1.19.x, which used two different directories in the MODELICAPATH, one for the package manager and one for the preinstalled MSL, leading to slightly confusing duplicate installations of MSL.

OMEdit loads MSL 4.0.0 by default in the Libraries Browswer. However, if one then loads a package using MSL 3.2.3, it is possible to unload MSL 4.0.0 and load MSL 3.2.3 just with a click of a button.

The second most notable feature is that a new general purpose ODE solver, named `gbode`, was introduced. This solver is a fully configurable single-step solver, supporting many different integration methods, both explicit and implicit, using either fixed time step or variable time step with error control, handling event detection and dense output for accurate resampling over a regular time grid. Implemented methods include Euler, Heun, Dormand-Prince, Gauss, Radau, Lobatto, Adams-Moulton, Fehlberg, SDIRK, ESDIRK, etc. Adaptive multi-rate algorithms are also available within this solver, although this feature is still experimental. This solver replaces previously available solvers like `euler`, `impeuler`, `trapezoid`, etc., which are now deprecated and will be removed in future versions of the tool.

The solver is currently only available via simulation flags, which can be set in OMEdit under Simulation Setup | Simulation Flags | Additional Simulation Flags (optional). It will be supported via drop-down menus in future releases. See the User's Guide under Solving Modelica Models for further information.

## OpenModelica Compiler (OMC)

The new front end has been further improved, with over a dozen bug fixes.

Some issues were fixed in the current backend, although most of the development work is now focused on the new backend, which can be optionally activated with the `--newBackend` compiler flag, and will become the default choice in a future release.

Regarding code generation several issues were fixed, including one that affected the ExternalMedia library, which is now fully supported by OpenModelica.

## C Runtime

Besides introducing the new `gbode` solver, some other issues were fixed. The support for external input from CSV files was improved and better documented. See here for a full list of closed issues.

## Graphical Editor OMEdit

Besides improved support of the Modelica Standard Library with the package manager, over a dozen issues were fixed, see the full list.

## FMI

Main highlights: - The FMI import feature allows to import an FMU as a block in a Modelica model. This feature was broken in versions 1.18.0 and 1.19.0, it is now functional again, with some limitations, see the User's Guide for further information. Support for this feature must be explicitly activated with the Enable FMU Import checkbox in the Tools | Options | Simulation | Translation Flags tab of OMEdit. - Support of FMI code generation using CMake, see the documentation in the User's Guide.

- Bug fixes.

See here for a full list of closed FMI issues.

## List of tickets closed in 1.20.0

List of closed tickets in 1.20.0. Over 80 issues were resolved.

## Next releases

A 1.20.1 bugfix version may be released if critical bugs are identified and resolved before January 2023. The next release 1.21.0 is planned to be beta-released in February 2023, and released in March 2023; it should include a completely restructured handling of model editing in OMEdit, including long awaited-for features like support of conditional connectors, parameter-depending dialog annotation, and faster rendering of complex diagrams.

Download it from: https://openmodelica.org

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.19.0...v1.20.0

# Release Notes for OpenModelica 1.19.2

Version 1.19.2 is a bugfix release, where some critical bugs that were present in 1.19.0 got fixed.

The most important one is #8772: parameter dependencies were not handled correctly in some cases, leading to some parameters being wrongly evaluated to zero, which also impacted multibody system animations, see #8938.

Some further remaining issues with directory names containing accented letters were fixed in #8777. A problem with the delay operator was also fixed, see #9116.

Here is the complete list of bug fixes in release 1.19.2.

Download it from: https://www.openmodelica.org

# Release Notes for OpenModelica 1.19.0

The new front end has been further improved, with over 40 bug fixes.

Several issues were fixed in the backend, most notably problems affecting event generation and issues involving algorithms and arrays, which led to a wrong diagnosis of under-determined system of equations. Overall, over 15 issues were addressed.

Regarding code generation 5 issues were fixed, mostly concerning corner cases that involved arrays, record, and slicing operators.

Remaining issues concerning Clock variables were resolved; so, starting from this version, the synchronous features of the Modelica language, in particular the Modelica.Clocked library, are now fully supported. The configuration of runtime and external libraries on Windows was substantially improved. A bug was fixed in daeMode that prevented correct event handling in state-less models, which now run correctly. Overall about 20 issues were fixed.

The most important new feature in 1.19.0 is the fully integrated package management and conversion script support in the GUI. We suggest you to read the Package Management section of the user's guide for an introduction to the basic concepts.

The package management functionality is now available under the File | Manage Libraries menu. It is possible to install supported (or experimental) open-source libraries from the internet, and upgrade them when newer versions are released; all the required dependencies are installed automatically. The Windows installer by default also installs the basic versions of the Modelica standard library, as a fallback in case internet connection is not available, e.g. in corporate environments. All other libraries are no longer supplied with the installer and must be installed via the package manager. Off-line use of the package manager will be improved in future versions.

When right-clicking on a library in the libraries browser, a new context menu item "Convert to Newer versions of used libraries" is available. This allows you to convert your library to newer versions of its dependencies, once you have installed them. If the newer version of the used library is backwards compatible with the previous one, this just changes the uses annotation, otherwise, the conversion script is run automatically. The most common use of this feature is to upgrade models or libraries that you developed using the Modelica library 3.2.3 to use Modelica 4.0.0. We recommend that you use this functionality on your own libraries only; for libraries that you download from the internet, it is best to wait for the developers to perform the conversion and release new versions of their libraries, that you can then get through the package manager.

Support of the dynamicSelect annotation has been improved, although it is still not 100% functional in all cases.

The plotting of results has been significantly improved; appropriate prefixes are now automatically selected to avoid getting very large or very small numbers on the Y-axis.

Overall, over 40 issues were fixed since the previous 1.18.1 release.

Work is on going to provide full support of parameter-depending conditional connectors, parameter-depending dialog annotations, and editing of parameter modifiers in redeclared classes. Implementing these features requires a fundamental re-design of the way OMEdit interacts with the OMC environment to get the required information. These features should become available, at least experimentally, in the future 1.20.0 release.

- Introduced support for interpolation in CS-FMUs by setting "canInterpolateInputs=true" in modeldescription.xml - Introduced support for getting partial derivatives in ME-FMUs by setting "providesDirectionalDerivative=true" - Lots of improvements to OpenModelica FMU export configurations (black box as well as source code FMUs). - Added source-code nonlinear solver CMINPACK to source-code FMUs

- Basic source-code FMU compilation with CMake; cross compilation with Docker now available on Windows.

About 10 issues fixed.

- Support of importing and exporting Units and UnitDefinitions to SSP files. - Support for getting directional derivative in OMSimulator using both Symbolic Jacobians and numerical approximation using KINSOL solver.

List of closed tickets in 1.19.0. About 180 issues were resolved.

A 1.19.1 bugfix version may be released if critical bugs are identified and resolved before July 2022. The next release 1.20.0 is planned to be beta-released in July 2022, and release in September 2022. On-going work to further improve the level of support of the Buildings library should ensure a significant improvement in the level of support of most Modelica libraries in that upcoming release.

Download it from: https://www.openmodelica.org

# Release Notes for OpenModelica 1.18.0

The development of the new front end continued further, after becoming the default in the previous version. The compiler can now successfully flatten 100% of the models of the Modelica Standard Library 3.2.3 and 4.0.0 that have an experiment annotation. It can also successfully flatten 100% of many other open-source Modelica libraries, such as Chemical, HelmholtzMedia, IBPSA, ModelicaTest, OpenIPSL, PNLib, PhotoVoltaics, PlanarMechanics, PowerGrids, PowerSysPro, PowerSystems, SystemDynamics, TAeZoSysPro, ThermofluidStream. The success ratio when flattening the models of the Buildings library is currently at 96%, on-going work aims at reaching 100% by the end of 2021. Overall, 20 front end issues were fixed since the last official release.

Regarding symbolic analysis and code generation, the handling of index reduction in non-trivial cases where the state constraints are spread among many equations has been improved by the introduction of the ASCC algorithm, coupled with the existing reshuffle loop algorithm; this had beneficial effects in particular on three-phase circuit models. Some bugs in the generation of symbolic jacobians for nonlinear systems were also fixed. Overall, 11 issues were resolved.

Full support of the spatialDistribution() operator was introduced, including accurate handling of events. Several low-level issues were resolved, involving memory leaks and segmentation faults.

The C++ runtime was improved to handle more Modelica language features that are used by the new frontend. The previously release OMC 1.17 had worse coverage for the C++ runtime since it used the new frontend by default without supporting it in the C++ code generator. With these improvements, the coverage of libraries improved significantly, also compared to previous versions of OpenModelica with the old frontend, since the new frontend handles more models correctly than the old one, see the regression report, column "Compilation".

Several new features were added to the plotting functionality of OMEdit, in particular: - a "Fit to Diagram" button was added close to the zoom buttons to automatically adjust the extent of a model diagram to its actual content; - the sign of plotted variables can now be toggled by means of the context menu on the variable legends, to compare directly variables that are opposite in sign; - appropriate multiples of SI units (e.g. mW, W, kW, MW, GW for power) are automatically selected for display based on the order of magnitude of the variable, to avoid very large or very small numbers on the plot axes; - the rendering of plots and parameter windows on large and/or high-resolution screens was further improved.

Several bugs were also fixed; in total, 27 issues were addressed.

FMI 2.0 export was further improved. OMSimulator development continues, over 30 issues were fixed.

The operation of power plants requires a good quality of the process data obtained through sensor measurements. Unfortunately, sensor measurements such as flow rates, temperatures, and pressures are subject to errors that lead to uncertainties in the assessment of the system's state. Operational margins are therefore set to take into account uncertainties on the system's state. Their effect is to decrease production because safety regulations put stringent limits on the thermal power of the plants. It is therefore important to compute the best estimates of the measurement uncertainties in order to increase power production by reducing operational margins as much as possible while still preserving system safety.

The best estimates can be obtained by combining data statistics with a knowledge a priori of the system in the form of a physical model. Data reconciliation is a technique that has been conceived in the process industry for that purpose. It is fully described in the VDI 2048 standard for the control and quality improvement of process data and their uncertainties by means of correction calculation for operation and acceptance tests".

An extension of Modelica to perform data reconciliation on Modelica models was developed together with EDF and is now fully implemented and integrated with the OMEdit GUI. The basic ideas are explained in this presentation, and a section DataReconciliation was added to the User's Guide, explaing how to use it step-by-step.

We are currently transitioning from the old trac issue tracker to the GitHub issue tracker, which is fully integrated with the GitHub revision control and continuous integration framework that we use for the development of OpenModelica. Eventually, the old trac tickets will be migrated onto the GitHub issue tracker. For the time being, old tickets are still managed on trac, while new ones are on GitHub. Overall, about 80 issues were addressed successfully since the 1.17.0 release.

- older tickets

- newer tickets

A 1.18.1 bugfix release is planned later this year with some critical bug fixes that have been identified and partially addressed, but need some more testing. The next release 1.19.0 is planned to be released in February 2022, close to the OpenModelica Workshop and Annual Meeting.

Version 1.19.0 is expected to contain a GUI integrated in OMEdit for library handling and conversions. It is also planned to successfully run 100% or close to 100% of the Buildings 7.0.1 library. This will be a major milestone, given the broad extent and complexity of that library.

Download it from: https://www.openmodelica.org

# Release Notes for OpenModelica 1.17.0

The new frontend has been further improved, and is now the default choice for all the OpenModelica tools. The `-d=newInst` flag no longer needs to be set in scripts. The old frontend is no longer maintained and will progressively be replaced also for the API interface used by OMEdit. 21 tickets were fixed since the previous 1.16.5 release.

Some issues were fixed in the backend, in particular regarding `homotopy` during initialization. Some improvements to code generation, in particular enhancing the support of the HelmholtzMedia library.

The MSYS environment used on Windows was updated to a more recent version, with several benefits: - clang is now also available on Windows and used by default instead of gcc for the compilation of the generated C code, providing much faster C compile time on Windows; - dynamic linking is used instead of static linking, further reducing the overall compilation time on Windows; - a more recent version of the QT library is used, which solves some issues with the rendering of features in OMEdit.

The Sundials solvers and basic linear algebra library KLU were upgraded to the most recent available versions, with benefits in performance and roubustness at runtime.

OpenModelica now supports both currently maintained versions of the Modelica Standard Library, MSL 3.2.3 and MSL 4.0.0. This means that you can use Modelica libraries that use either version of the MSL, or create new ones that do so. Automatic conversion of existing libraries from MSL 3.2.3 to MSL 4.0.0 is currently not yet available, it is planned for version 1.18.0.

Please note that the synchronous features in MSL 4.0.0 are still not fully supported, so we suggest not to rely on them in this version of the tool. Better support is planned for version 1.18.0.

The user experience with OMEdit is significantly improved in version 1.17.0, in particular for the Windows version, where the compilation time was drastically reduced by using clang instead of gcc and by dynamic linking instead of static linking of the simulation executable.

Thanks to the upgrade of the employed QT graphics libraries, several issues that plagued the graphical user interface are now resolved.

Replaceable classes continue to have graphical support in OMEdit, even though parameters in redeclared classes cannot yet be modified from the GUI, thus requiring to switch to text mode to do so. The new front end can also be used for some of the API functions called by OMEdit to render the model diagrams, making the response of the GUI much faster. Please note that both these features are currently optional and needs to be activated by setting Tools | Options | General | Enable replaceable support and Enable new frontend use in the OMC API (faster GUI response). These settings are retained from the previous installation upon version upgrading.

Unsaved code was sometimes lost when switching among different windows in OMEdit, this is no longer happening in this release. Several issues that caused occasional crashes of the GUI were also fixed.

OMEdit now can use both currently maintained versions of the Modelica Standard Library, MSL 3.2.3 and MSL 4.0.0. Please note that the Modelica.Clocked package in MSL 4.0.0 is still not handled in a completely reliable way, while most other models work equally well in the two versions.

When starting the program for the first time after installation, one can choose among three options: load MSL 3.2.3 automatically, which however prevents using libraries that need MSL 4.0.0; load MSL 4.0.0 automatically, which prevents using libraries that need MSL 3.2.3; not loading any version of the library upon starting OMEdit, leaving it to the tool to load the right one when a model or library is opened, thanks to the uses() annotation. The latter option allow to handle different projects that use either version of the MSL without problems, of course one at a time. This choice can be later modified by going to the Tools | Options | Libraries menu and by adding or removing the Modelica library from the automatically loaded system libraries, and/or by modifying the specific version that gets loaded.

Proper support of the package manager from the GUI, including conversion scripts to upgrade existing libraries from MSL 3.2.3 to MSL 4.0.0, is planned for version 1.18.0.

16 bug fixes were made to OMEdit in version 1.17.0, to increase usability of the GUI.

Until version 1.16.x, OpenModelica was built on Windows, Linux, and macOS. The core functionality of the tool is implemented in Linux, and is ported to Windows using the MinGW environment, and on macOS using the macports environment.

Unfortunately, many libraries OpenModelica depends on are not regularly updated on macports, which caused the Mac build to break every other day. Given our limited resources, we can't take on the burden of the required macports maintenance, so we regret to inform you that we decided to stop providing builds of OpenModelica for macOS. It is still possible to run OpenModelica on the Mac by running a virtual machine with a Linux installation of OpenModelica, see the instructions on the Mac download page. We are still trying to make it possible to build OpenModelica from sources on macOS, please check ticket #6306 for the latest updates and if you want to contribute to the effort. However, we do not guarantee this will be always possible in the future.

FMI 2.0 export and FMI simulation with OMSimulator was further improved.

OMSimulator is now integrated into pypi and installed via pip.

A prototype Flat Modelica code export feature is now available, a result of the Emphysis project and eFMI on-going standardization effort. It can be activated with the compilation flag.

The Modelica package manager is still only available from the command line in this release. We plan to integrate it the OMEdit GUI for the 1.18.0 release, together with conversion scripts.

Download it from: https://www.openmodelica.org

# Release Notes for OpenModelica 1.16.5

This hopefully the final bugfix release of 1.16.0, which addresses an issue that affected diagrams in OMEdit under certain conditions.

## What's Changed

- Keep the NFApi settings (#7215) by @adeas31 in https://github.com/OpenModelica/OpenModelica/pull/7217

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.16.4...v1.16.5

# Release Notes for OpenModelica 1.16.4

This is a further bugfix release of 1.16.0, which addresses an issue that affected diagrams in OMEdit under certain conditions.

## What's Changed

- Move the nfAPI and nfAPINoise settings to general page (#7171) by @adeas31 in https://github.com/OpenModelica/OpenModelica/pull/7175

- Prepare for 1.16.4 by @adrpo in https://github.com/OpenModelica/OpenModelica/pull/7186

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.16.3...v1.16.4

# Release Notes for OpenModelica 1.16.2

This is a bug fix release.

## What's Changed

- Omedit fixes by @adeas31 in https://github.com/OpenModelica/OpenModelica/pull/6982

- Fixes 1.16 by @adeas31 in https://github.com/OpenModelica/OpenModelica/pull/7004

- fix ticket #6300, use NF for getElementAnnotations if -d=nfAPI is on by @adrpo in https://github.com/OpenModelica/OpenModelica/pull/7055

- partial fix for #6287 and fix for #6288 by @adrpo in https://github.com/OpenModelica/OpenModelica/pull/7056

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.16.1...v1.16.2

# Release Notes for OpenModelica 1.16.1

This is a further bugfix release of 1.16.0

## What's Changed

- fix #6167 allow partial handling in NF when -d=nfAPI is on by @adrpo in https://github.com/OpenModelica/OpenModelica/pull/6898

- Do not put libOMEdit.a in build/ by @sjoelund in https://github.com/OpenModelica/OpenModelica/pull/6908

- Copy OMEdit fixes from master to v1.16 by @adrpo in https://github.com/OpenModelica/OpenModelica/pull/6911

- Use assert instead of Q_ASSERT by @adeas31 in https://github.com/OpenModelica/OpenModelica/pull/6929

- Copy #6174 fixes to 1.16 by @adrpo in https://github.com/OpenModelica/OpenModelica/pull/6939

- Backport the new ZMQ flags to 1.16 by @sjoelund in https://github.com/OpenModelica/OpenModelica/pull/6950

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.16.0...v1.16.1

# Release Notes for OpenModelica 1.16.0

The new frontend has been further improved, with enhanced support of records and arrays. 33 tickets were fixed since the previous 1.14.0 release. The new front-end can now handle 100% of the Modelica Standard Library 3.2.3 models.

Improvements to the back-end:

- new minimal tearing option `--minimalTearing` to disable tearing except for discrete variables

- improved symbolic Jacobian evaluation option `--simJacConstantSplit` reuses constant part of the Jacobian

- improvements to dynamic state selection and common subexpression elimination

- new ASCC algorithm replaces and improves resolveLoops algorithm, allowing to detect high-index problems with indirect structural state constraints, e.g. in three-phase AC circuits

- homotopy operator now used on first try by default

- linearized model export also available in Matlab, Python, and Julia with option `--linearizationDumpLanguage`

Improvements to code generation and runtime:

- Better support for models with records

- CVODE solver from SUNDIALS added;

- 2 methods available: BDF (stiff) and Adams-Moulton (non-stiff)

It is now possible to build a version of OMC with parallel Jacobian evaluation using OpenMP

- On Windows build OMC with `make -f Makefile.omdev.mingw omc -j4 USE_PARJAC=yes`

- On Unix configure with `--enable-parjac` and build OMC.

- Only DASSL and IDA can use parallelized symbolic Jacobians.

- Simulate with `-jacobianThreads=<numberOfThreads>` or set environment variable `OMP_NUM_THREADS=<numberOfThreads>` to use a specific number of threads. Otherwise all available threads will be used.

Replaceable classes now have graphical support in OMEdit. This feature was planned to be included in release 1.15.0, but it eventually turned out to be more convenient to merge it in the 1.16.0 release. Support for replaceable elements in OMEdit is currently limited to redeclare statements without parameter modifiers. This is enough to handle Modelica.Media medium models in Modelica.Fluid components. Please note that this feature is currently optional and needs to be activated by setting ToolsGeneral|Enable replaceable support in OMEdit.

Over 50 bug fixes were made to OMEdit to increase usability of the GUI.

OMSimulator GUI improved: text editing of SSP models, undo/redo, delete components, etc.

Many FMI export bug fixes and improvements to increase usability of OMC-generated FMUs.

FMI/CS 2.0 now includes CVODE solvers (previously only fixed-step forward Euler) and customization via simulation flags.

Successful integration of Modelon's license manager for encrypted libraries. A special version of OMC available to Consortium members can now handle encrypted libraries, preventing source code browsing, and license management, via Modelon's license manager, embedded in the encrypted library.

Improved Modelica package management. The `conversion(noneFromVersion)` annotation is now fully supported, which means for example that OpenModelica will automatically use the Modelica Standard Library 3.2.3 even for libraries that have a uses annotation pointing to earlier MSL versions, e.g. 3.2.2 or 3.2.1, because the `conversion(noneFromVersion)` annotations in the MSL specify that 3.2.3 can be used instead of 3.2.2 or 3.2.1 without any conversion script, i.e., it is fully backwards compatible. A full-fledged Modelica package manager is also included in OpenModelica 1.16.0, currently only with a command line interface; integration in the GUI is planned for the next 1.17.0 release, together with conversion scripts.

## New Contributors

- @mflehmig made their first contribution in https://github.com/OpenModelica/OpenModelica/pull/302

- @stheid made their first contribution in https://github.com/OpenModelica/OpenModelica/pull/752

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.15.0-dev...v1.16.0

# Release Notes for OpenModelica 1.14.2

A bug fix release for v1.14.1, fixing among other things compilation on Ubuntu 20.04.

## What's Changed

- Fixes ticket:5733 Don't use the qualified path by @adeas31 in https://github.com/OpenModelica/OpenModelica/pull/647

- [NF] Fix some Expression.map*Opt functions. by @perost in https://github.com/OpenModelica/OpenModelica/pull/656

- ticket:5778 Fixed users guide links by @adeas31 in https://github.com/OpenModelica/OpenModelica/pull/666

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.14.1...v1.14.2

# Release Notes for OpenModelica 1.14.0

The most dramatic enhancement of the OpenModelica Compiler is the New Frontend, which on the average gives a factor of 10-20 speed improvement in the flattening phase of compilation. The new frontend is default in this release, but a feature is implemented that allows the user to switch to the old frontend if problems appear for a specific model The speed of the OMEdit GUI has only slightly increased in this version, since it is still dependent mostly on the old frontend. Further GUI speed increases are available in the coming OpenModelica.1.15.0. About 200 issues have been fixed, including enhancements, compared to the previous 1.13.2 release. The bug fixes are on trac.

OpenModelica Compiler New Frontend news: • Implementation of expandable connectors completed, a rather large piece of work. • A number of smaller enhancements and fixes • The New Frontend (NF)gives slightly better simulation coverage on MSL 3.2.3 than the Old Frontend • The New Frontend is on the average about 20 times faster on flattening. • Remaining work is mainly on further bug fixing and testing the new frontend for all other libraries, as well as more work on modifiers of arrays in conjunction with non-expanded arrays. (The array modifiers have now been implemented in 1.16.0 but not yet it 1.14.0 in order to not delay the 1.14.0 release)

- Drag and drop for the text layer. • Auto completion of class names, components and annotations. • GUI for data reconciliation – a method for increasing sensor data precision • Improved duplication functionality for copying classes. • Better handling of Compiler flags. • Partly completed: annotations for dynamic icon update. • Support for connectorSizing annotation • Several bug fixes. You can find the list here. • Docs: https://openmodelica.org/doc/OpenModelicaUsersGuide/latest/omedit.html. • Autocomplete annotations. • Support for Icon/Diagram map annotation • Copy paste functionality • Reset OMEdit settings/options. • Array plots update on re-simulation • Support for connectorSizing annotation. • Drag and drop class names to text layer in OMEdit • OMPlot: Improved plotting e.g., top and bottom margins for better view, snap to curve etc. • GUI support for replaceable libraries is being tested in a separate branch and will be made available in the coming 1.15.0 release.

- A new more efficient and correct implementation of arrays and records.

- The FMI OMSimulator API calls are now also available in the OMC API functions, e.g. for use from OMNotebook, Jupyter notebooks.

- Added possibility to generate analytic Jacobians for linear strong components • Use flag LSanalyticJacobian to enable analytical Jacobian for linear loops. Default false.

- Added output language options for linearization: matlab, python, julia. • Available with --linearizationDumpLanguage=modelica/matlab/python/julia. Default is modelica.

- Unified Jacobian evaluation from DASSL and IDA integrators • Added result check for linear solvers Lis, Klu, Total Pivot and Umfpack if a residual function is available. • Improved debug dumping

• -d=bltdump (Index reduction information) • -d=initialization
• -d=dumpLoops

- Improved warning for iteration variables:

• Only warn about non-linear iteration variables with default start attribute. • Other variables have no influence on simulation at all.

- Build instructions for OpenModelica on Windows Subsystem for Linux • Improved Jacobian evaluation with translation flag -d=symJacConstantSplit (requires --generateSymbolicJacobian). Generate Jacobians with separated constant part to split equations that are independent of the seed vector. These equations only need to be evaluated only once per Jacobian evaluation.

- Homotopy: Use simplified version only during initialization to avoid errors during matching and differentiation. • Logging for Homotopy path fixed so log can be loaded in OMEdit. • Support general function call differentiation for equations in residual form. • Equations in residual form don't fail during index reduction any more.

Bug fixes to FMI export, see below

Full Changelog: https://github.com/OpenModelica/OpenModelica/compare/v1.14.0-dev...v1.14.0