v9.6.1

ModelingToolkit v9.6.1

Diff since v9.6.0

Merged pull requests:

• fix: fix io handling in structural_simplify, input_output_handling tests (#2547) (@AayushSabharwal)
• Fix iteration bounds in tearing_with_dummy_derivatives (#2557) (@YingboMa)
• Update for StructuralIdentifiability API changes (#2561) (@ChrisRackauckas)

Closed issues:

• MethodError Raised When Running "Parameter Identifiability in ODE Models" Tutorial (#2551)

v9.6.0

ModelingToolkit v9.6.0

Diff since v9.5.0

Merged pull requests:

• add docs for sampled-data systems (#2410) (@baggepinnen)
• Add getindex/setindex! methods for MTKParameters with ParameterIndex (#2531) (@MasonProtter)
• Avoid computing inputs if IO is unspecified (#2537) (@baggepinnen)
• fix: fix history function in DDEProblem constructor (#2541) (@AayushSabharwal)
• docs: update FAQ section with relevant MTKv9 questions (#2542) (@AayushSabharwal)
• refactor: implement new additions to SII interface (#2544) (@AayushSabharwal)
• Add missing updates to sampled-data docs (#2560) (@baggepinnen)

Closed issues:

• varmap_to_vars output and MTKParameters in ODEProblem are Different (#2525)
• Problem with DDEProblem and MTK 9 (#2530)
• Error Accessing Parameter Argument of Integrator during continuous_events Callback (#2538)
• guess is sometimes ignored (here with linearize) (#2539)
• Create a function for retrieving the default t iv? (#2552)

v9.5.0

ModelingToolkit v9.5.0

Diff since v9.4.0

Merged pull requests:

• Add event support mtkmodel (#2427) (@cgutsche)
• Specialize symbolic Struct (#2532) (@YingboMa)

Closed issues:

• Discrete Events Behaving Unexpectedly (#2528)

v9.4.0

ModelingToolkit v9.4.0

Diff since v9.3.0

Merged pull requests:

• Add support for component array in @mtkmodel (#2368) (@ven-k)
• feat: add @defaults to @mtkmodel (#2437) (@ven-k)
• Fix updating default value metadata of conditional parameters (#2438) (@ven-k)
• chore: add 0.12 of DynamicQuantities (#2479) (@ven-k)
• CompatHelper: bump compat for DynamicQuantities to 0.12 for package docs, (keep existing compat) (#2498) (@github-actions[bot])
• Parse constants in @mtkmodel (#2499) (@ven-k)
• fix: fix variable_index (#2514) (@AayushSabharwal)
• feat: add SolverStepClock (#2517) (@baggepinnen)
• fix: type of array in the mtkmodel's f (#2521) (@ven-k)
• [skip ci] add isconnection to ignored typos words (#2523) (@ArnoStrouwen)
• fix: avoid scalarizing params in structural_simplify, variable defaults in get_u0 (#2524) (@AayushSabharwal)

Closed issues:

• Move @variables and @parameters defaults to the ODESystem defaults keyword to support defaults that depend on components. Or add a @defaults block to support out of order defaults manually. (#2416)
• "Ignore" option for connectors (#2422)
• Callback Example gives MethodError with MTK 9 (#2496)

v9.3.0

ModelingToolkit v9.3.0

Diff since v9.2.0

Merged pull requests:

• Provision to enforce types in parameters, variables and structural_parameters in @mtkmodel (#2500) (@ven-k)
• Expose a non dummy derivative index lowering (#2510) (@ChrisRackauckas)
• 🚑 pass type to var generation (#2511) (@ven-k)
• Initialization on non-DAE models (#2512) (@ChrisRackauckas)
• Add a tutorial for initialization handling (#2518) (@ChrisRackauckas)
• Add init for maximum (#2519) (@YingboMa)

Closed issues:

• @mtkmodel does not handle specification of variable type (#2491)
• Interface improvements for initialization (#2506)
• Ability to use derivatives (without dummy derivatives) in the initialization equations (#2513)

v9.2.0

ModelingToolkit v9.2.0

Diff since v9.1.0

Merged pull requests:

• Fix up initializesystem for hierarchical models (#2403) (@ChrisRackauckas)
• docs: update docs for MTKv9 (#2489) (@AayushSabharwal)
• OptimizationSystem: Generate oop constraint derivatives (#2492) (@Vaibhavdixit02)
• Fix testing infrastructure (#2495) (@ChrisRackauckas)
• Update NEWS.md for DAE Initialization changes (#2503) (@ChrisRackauckas)

Closed issues:

• structural_simplify on an OptimizationProblem (#1565)
• Initial conditions via observed variables (#1836)
• Overridden default set on observed quantity not propagating to its alias (#1968)
• How to prevent breakage from changes to structural_simplify (#2000)
• substitute(::ODESystem) does not substitute in events (#2059)
• Compute initial states for u0 if u0 is parametric (#2103)
• Advanced initialization (#2151)
• WARNING: importing deprecated binding Symbolics.@register into ModelingToolkit. (#2197)
• Pretty printing list of parameters. (#2481)

v9.1.0

ModelingToolkit v9.1.0

Diff since v9.0.1

Merged pull requests:

• Add StateMachineOperators (#2441) (@YingboMa)
• CompatHelper: bump compat for DiffEqCallbacks to 3, (keep existing compat) (#2486) (@github-actions[bot])
• CompatHelper: bump compat for ModelingToolkit to 9 for package docs, (keep existing compat) (#2487) (@github-actions[bot])
• SelectedUnknown -> SelectedState (#2494) (@YingboMa)

Closed issues:

• Parameter Identifiability Analysis (#170)
• Block calculations of derivative quantities (#270)
• Nicer parameter indexing (#318)
• NetworkSystem (#341)
• How to remake with a Vector{Pair}? (#472)
• Latexify for ODEs uses inconsistent notation for variables. (#533)
• Comment on terminology: parameter vs. (independent) variable t (#564)
• Symbolic arrays instead of arrays of symbolics (#605)
• Fix and/or test NonlinearSystem conversion from ReactionSystems (#639)
• Better error messages for missing equations in ODESystems (#803)
• Implement combine for inheritance of systems (#807)
• Deprecate gensym naming (#831)
• Default value metadata (#846)
• modelingtoolkitize tutorial: automated sparsity handling (#872)
• Detecting and solving small dense linear subsystems symbolically after tearing (#887)
• Discrete-Time (Sub-)Systems (#894)
• Documenting how to generate namespaced names for AbstractSystem variables (#902)
• Visual model representation and interaction (#918)
• structural_simplify(SDESystem) throws an error (#928)
• Delay differential equation handling (#955)
• Support for DAE's without differential terms (#969)
• logo? (#970)
• Better variable identification (#981)
• State selection (#988)
• exporting MTK model to FMU (#994)
• Creating an "ImageProblem" problem type in MTK (#1012)
• Nested systems with symbolic defaults/initial values don't get de-aliased (#1013)
• Support for derivatives/interpolation with simplified systems? (#1014)
• Nonlinear optimal control tutorial equation inconsistency (#1024)
• ControlSystem without defined loss function (#1041)
• Documentation comments (#1053)
• modelingtoolkitize doesn't work with pre-allocated variables (#1058)
• Dispatchable systems (#1071)
• Add sparsity to ODEProblem on construction (#1087)
• Parameter representation for controls (#1088)
• Variable access feature is very slow (#1102)
• Input & output systems (#1111)
• provide type stable access to ODESolution by Num observed object (#1112)
• Namespacing (#1117)
• Allowing discrete Difference equations in ODESystem (#1122)
• extend forget a variable ... (#1133)
• Supporting multi-clock discrete systems (#1137)
• Using Jacobian sparsity structures of large ODEs/PDEs downstream (#1160)
• addition on Differentials not defined (#1161)
• structural_simplify on DiscreteSystem says "this should never happen" (#1166)
• PDESystem fails (#1179)
• Coupling MTK with time discrete control (#1180)
• Problem with 2D Poisson-Eqn. PDE (#1204)
• Difference Operator Not Working Correctly (#1206)
• Error when inverting matrix of dependent variables (#1231)
• StructuralIdentifiability tutorial? (#1232)
• release notes / news equivalent for breaking changes or new features (#1245)
• Functions created by build_function should supported passing parameters using NamedTuples and Dicts (#1259)
• parameters in modelingtoolkit don't support vector ? (#1271)
• incorrect ODEs when child ODESystem contains ParentScope'd state (#1274)
• Documentation (#1280)
• Example of potential compile time growth issue (#1286)
• very slow when rebuild ODEProblem (#1285)
• Dimension problem for the variable multiplication (#1291)
• Support for finding nullclines (#1294)
• StackOverflowError, can't handle large system (#1297)
• Error when simulating ODESystem with difference equations (#1304)
• Time-shift operator for discrete-time control systems (#1307)
• How to preserve compilation of observed runtime generated function? (#1312)
• Algebraic equations are delayed one step too much in DiscreteSystems (#1330)
• Incorrect observed variables after structural_simplify (#1345)
• Tutorial for Spring-Mass-System resulting in Stack Overflow Error (#1353)
• Tearing partitioning doesn't consider solvability (#1362)
• Solving errors (#1365)
• Some symbolic parameters are not replaced by numeric during solve (#1369)
• Automatic inference of time step for DiscreteSystems (#1374)
• Incorrect solution for DiscreteSystem (#1378)
• Unable to build torn function (#1379)
• Use tearing information directly in codegen (#1387)
• Inputs outputs in MTK (#1411)
• Spring-mass tutorial fails on MTK v8.3.2 (#1434)
• ODAEProblem should try to transform mass matrices to the identity matrix (#1435)
• Parameter Identifiability in ODE Models (#1441)
• Using structural_simplify on SDE System (#1447)
• docs for full_equations() (#1459)
• Long compilation time some numbers + included examples (#1461)
• Easier vectorial differential equations (#1485)
• Julia REPL crash when using NewtonRaphson on a semi-big problem (#1507)
• mul_float: types of a and b must match error in ModelingToolkit (#1515)
• Allow extend System to override previous equations (#1518)
• Support for scalar parameter and initial condition mappings (#1520)
• How to represent Modelica style If-Equations using MTK (#1523)
• UndefRefError When modelingtoolkitizeing a system that uses DEDataArrays (#1564)
• Slow access to solution via symbols (#1585)
• Implicit DAE observed indexing is broken (#1589)
• Constructing an ODEProblem with a non-numeric parameter throws a Float conversion error. (#1595)
• Difference ODEProblem ODAEProblem (#1611)
• Compatibility with DataInterpolations.jl (#1615)
• ODAE problem does not acknowledge retcodes when solving (#1633)
• Passing initial state of submodel silently fails (#1638)
• Latex rendering issues (#1658)
• sparsity pattern J vs J-gamma*I (#1668)
• MTK cannot identify independent variables with new Symbolics convention (#1706)
• Vector parameters not supported (#1723)
• ODAEProblem's observed function is not always topologically sorted (#1726)
• Indexing solutions with many symbolics fails (#1737)
• Handling of wrongly namespaced variables (#1746)
• Homogenize parameters by default (#1748)
• Symbolic variables don't work for several inbuilt functions (#1749)
• Optimization tutorial fails (#1781)
• Sanity type-checking for equations (#1788)
• Crashing REPL w/ malformed system (#1801)
• ODEProblem creation fails for Unitful models (#1803)
• DtLessThanMin when solving Mixed Difference Differential Equations test example (#1809)
• feature request: make remake take partial parameter maps (#1810)
• Unit checking error message (#1813)
• State reordering on structural_simplify (#1817)
• Update the var_to_name map when vars are updated (#1825)
• Cannot determine ordering of Dual tags ForwardDiff (#1867)
• solution indexing with symbolic expressions that include parameters (#1874)
• MTK -- basic questions (#1925)
• thoughts on being stricter when constructing Problems from systems? (#1933)
• Symbolic indexing of the solution is slow (#1944)
• Vsode ParseError: KaTeX parse error: (#1958)
• UndefVarError when retrieving solution of ODAEProblem without prior index lowering (#1961)
• getproperty incompatible with ParentScope and DelayParentScope (#1973)
• Conductor as a downstream test on MTK (#1979)
• paramters in optimizations FAQ (#1982)
• Cryptic Tsit5() error message when building a simple electrical circuit (#2006)
• Unexpected UndefVarError (#2007)
• Variable metadata connector documentation (#2013)
• Simulation of hybrid system (#2018)
• Compilation of ODEProblem generated from MTK system fails on GPU even if original problem is GPU-compatible (#2026)
• MTK: Scaling of time/parametric plots? (#2076)
• Composable NonlinearSystem fails but runs as an ODESystem (#2106)
• structural_simplify unexpected ERROR when applied twice in a row (#2108)
• Not an issue... but trying to understand MTK (#2111)
• Indexing solution with symbolic array is slow (#2112)
• Q: parameters in MTK (#2130)
• MTK Bug? Some observed are not computed? (#2136)
• Enable `solve(...;save_idxs=) for not integer indexes (#2139)
• Possible regression when simplifying system to 0 states (#2141)
• Discrete systems in MTK (#2165)
• Incomplete derivative expansion with DataInterpolations (#2169)
• remake doesn't work with mapped parameters (#2171)
• [FR] Allow named container for parameters when converting to DEProblem (#2195)
• Documentation tab for various API function (#2224)
• Add more complete DynamicQuantities support (#2230)
• Handling of dependent defaults (#2238)
• Split tunables from the rest of heterogeneous parameter (#2260)
• Add tunables in ODEProblems (#2261)
• Next major release checklist (#2262)
• Array parameters/variables with @mtkmodel (#2269)
• Recent bug: parameter tuples no longer preserve parameter types (#2296)
• Do not split parameters into tuple of vectors by default (#2311)
• Improve documentation (#2326)
• Inconsistency in structural_parameters and non-contextualized error message (#2341)
• ERROR: ArgumentError: System rc_model: variable resistor₊v does not exist (#2369)
• Deprication of all_dimensionless and how to adapt unit check in Catalyst? (#2459)
• MTK 9 migration guide (#2463)
• System can't structural_simplify when using multiple SampledData blocks (#2475)

v9.0.1

ModelingToolkit v9.0.1

Diff since v9.0.0

Merged pull requests:

• Fix and update documentation for v9 (#2478) (@ChrisRackauckas)
• fix: fix jacobian generation for NonlinearSystem (#2480) (@AayushSabharwal)

Closed issues:

• MTK v9 with split=true breaks obtaining parameters with SymbolicIndexingInterface. (#2485)

v9.0.0

ModelingToolkit v9.0.0

Diff since v8.75.0

Merged pull requests:

• [BREAKING Don't merge] Support DynamicQuantities (#2349) (@YingboMa)
• add component-based hybrid system test (#2355) (@baggepinnen)
• Getcoeffchunk (#2393) (@chriselrod)
• Preserve staticarrays in the problem construction (#2399) (@ChrisRackauckas)
• Fix some warnings (#2405) (@isaacsas)
• build(deps): bump crate-ci/typos from 1.16.25 to 1.17.0 (#2419) (@dependabot[bot])
• CompatHelper: bump compat for DynamicQuantities to 0.11, (keep existing compat) (#2424) (@github-actions[bot])
• Replace MacroTools with ExprTools & Base.remove_lines! (#2425) (@oxinabox)
• Consistent variable creation (#2428) (@YingboMa)
• build(deps): bump actions/cache from 3 to 4 (#2430) (@dependabot[bot])
• fix(pdesystem): parameters are vector of Num instead of vector of pairs when analytic is also passed (#2431) (@sathvikbhagavan)
• refactor: rename states to unknowns, and related changes (#2432) (@AayushSabharwal)
• feat!: deprecate ODAEProblem (#2435) (@AayushSabharwal)
• refactor!: require systems to be completed before creating XProblem/XProblemExpr (#2436) (@AayushSabharwal)
• test: uncomment tests (#2439) (@AayushSabharwal)
• refactor!: remove old discrete system (#2440) (@AayushSabharwal)
• feat!: add common definitions of t and D (#2442) (@AayushSabharwal)
• fix!: require explicit independent variable for ODESystem (#2443) (@AayushSabharwal)
• Update bifurcation_diagram_computation.md (#2444) (@rveltz)
• Update bifurcation_diagram_computation.md, add periodic orbits comput… (#2445) (@rveltz)
• chore: remove undefined exports (#2446) (@sathvikbhagavan)
• feat!: use SciMLStructures and add new MTKParameters (#2447) (@AayushSabharwal)
• build(deps): bump codecov/codecov-action from 3 to 4 (#2448) (@dependabot[bot])
• build(deps): bump crate-ci/typos from 1.17.0 to 1.18.0 (#2449) (@dependabot[bot])
• Have CI tests depend on formatter passing (#2451) (@chriselrod)
• [skip ci] Update dependabot.yml (#2452) (@ArnoStrouwen)
• ci: explicitly specify token for codecov (#2454) (@thazhemadam)
• Pin JuliaFormatter (#2456) (@YingboMa)
• docs: use @mtkbuild instead of manually calling complete (#2460) (@AayushSabharwal)
• Fix test groupings and test setup (#2465) (@ChrisRackauckas)
• docs: update NEWS.md with v9 update notes (#2466) (@AayushSabharwal)
• build: bump compat of DomainSets (#2467) (@sathvikbhagavan)
• Correct number of srcs in complete (#2468) (@Keno)
• feat!: do not scalarize parameters, fix some tests (#2469) (@AayushSabharwal)
• Format (#2471) (@YingboMa)
• docs: update NEWS.md (#2473) (@AayushSabharwal)

Closed issues:

• ODESystem created calling external vector valued function (#1828)
• Missing initialization of discrete-to-continuous communication parameter (#2356)
• ModelingToolkit does not save array as static arrays (for initial conditions and parameter values) (#2398)
• Internation functions for conversion between various forms of representing states/parameters etc. (e.g. symbolics or indexes) (#2404)
• Cannot access observed variables in NonlinearSolution (#2420)
• Precompilation of ModelingToolkit reports two errors on Julia 1.10 (#2429)
• Basic (but incomplete) system construction throws incorrect error on get_system (#2464)
• structural_simplify of SDESystem (#2476)

v8.75.0

ModelingToolkit v8.75.0

Diff since v8.74.1

Merged pull requests:

• CompatHelper: bump compat for StructuralIdentifiability to 0.5 for package docs, (keep existing compat) (#2365) (@github-actions[bot])
• CompatHelper: bump compat for NonlinearSolve to 3 for package docs, (keep existing compat) (#2376) (@github-actions[bot])
• fix: remove evals from model parsing (#2379) (@ven-k)
• feat: add new all-symbols methods from SII (#2386) (@AayushSabharwal)
• refactor: handle NullParameters, fix independent_variable_symbols for multivariate systems (#2391) (@AayushSabharwal)
• @inbounds @boundscheck does not work; should have tested it earlier. (#2392) (@chriselrod)
• Update abstractsystem.jl with :get_name (#2395) (@cadojo)

Closed issues:

• Broadcast inside of @mtkmodel macro causes precompilation failures when put into a package (#2377)
• Load error with @mtkbuild (#2390)
• Support remake to update individual variables/species in new MTK version (#2396)
• Erroe when plotting observed variable(s) (#2397)