v9.26.0

ModelingToolkit v9.26.0

Diff since v9.25.0

Merged pull requests:

• document the fully_determined kwarg to structural_simplify (#2880) (@MasonProtter)
• Detect diagonal noise in SDESystem (#2882) (@MasonProtter)
• Pass down documented kwargs in structural_simplifiy (#2885) (@ChrisRackauckas)
• fix: create specialized isdiag for symbolics in noise matrix (#2886) (@AayushSabharwal)
• feat: allow specifying nothing as default value to skip it (#2887) (@AayushSabharwal)

Closed issues:

• Diagonal noise not detected during lowering of System with @brownian variables (#2490)
• @discrete_events or @continuous_events not working with acausal modeling framework (#2849)
• fix requirement for SDESystems to take Num inputs (#2868)

v9.25.0

ModelingToolkit v9.25.0

Diff since v9.24.0

Merged pull requests:

• Extend initialization equations (#2846) (@hersle)
• Handle modelingtoolkitize for nonlinearleastsquaresproblem (#2847) (@ChrisRackauckas)
• Left-to-right expand observed equations into defaults during initialization (#2861) (@hersle)
• Create independent variables with @independent_variables (#2862) (@hersle)
• Capture observed dependence on unknowns in simplified nonlinear systems (#2863) (@hersle)
• Error missing defaults (#2864) (@hersle)
• Extend metadata (#2867) (@hersle)
• refactor: avoid substitute warning when not needed (#2869) (@SebastianM-C)
• Add more documentation (#2871) (@hersle)
• Export more functions relating to system initialization (#2872) (@hersle)
• Restore error when unknowns in the initialization system don't have guesses (#2877) (@hersle)
• Some repo cleanup (#2878) (@ChrisRackauckas)
• Allow for setting fully_determined=true in initialization (#2879) (@ChrisRackauckas)

Closed issues:

• Duplicate Global Parameters (#992)
• Documentation for equations, equations, full_equations (#1822)
• Some ODESystem fields such as metadata are lost when using the extend function (#2502)
• Allow altering a symbolic parameter default value after creation. (#2650)
• Add NonlinearLeastSquaresProblem dispatch for modelingtoolkitize (#2669)
• Error when plotting multiple (not single) observable in Symbol form (#2739)
• Custom independent variable leads to underdetermined initialization system (#2818)
• Precompiling MTK when --depwarn=yes or --depwarn=true causes deprecation warning (#2827)
• extend() does not pass on initialization equations (#2845)
• testing against Julia 1.6 LTS dropped (#2854)
• Subsystem not namespaced when substituted coefficient is 1 (#2855)
• Cannot initialize well-defined ODE with defaults (#2859)
• Helpful error for missing guesses has disappeared (#2873)

v9.24.0

ModelingToolkit v9.24.0

Diff since v9.23.0

Merged pull requests:

• Better error throwing on ill-formed SDESystems (#2833) (@ChrisRackauckas)
• fix: fix deepcopy for SteadyStateProblem (#2840) (@AayushSabharwal)

Closed issues:

• Regression: Cannot deepcopy SteadyStateProblem (#2837)

v9.23.0

ModelingToolkit v9.23.0

Diff since v9.22.0

Merged pull requests:

• fix: fix unknowns not present in initialization system in linearization (#2809) (@AayushSabharwal)
• fix: infer oop form for SDEProblem/SDEFunction with StaticArrays (#2834) (@AayushSabharwal)

Closed issues:

• Miss-compilation when Hold is applied to delayed discrete variable (#2701)
• Unable to simualte SDEs with static array u0/ps (#2814)
• EXCEPTION_ACCESS_VIOLATION when solving ODEProblem (#2835)

v9.22.0

ModelingToolkit v9.22.0

Diff since v9.21.0

Merged pull requests:

• feat: dump more variable metadata (#2811) (@AayushSabharwal)
• fix: fix MTKParameters creation using defaults of parameters not in the system (#2821) (@AayushSabharwal)
• feat: complete eval_expression and eval_module support (#2826) (@AayushSabharwal)

Closed issues:

• A mysterious crash with defaults (#2817)
• SDE simulations broken (#2829)

v9.21.0

ModelingToolkit v9.21.0

Diff since v9.20.0

Merged pull requests:

• Add nameof dispatches on operators (#2822) (@ChrisRackauckas)
• Accelerate connection sets merging with union-find (#2824) (@YingboMa)
• Make eval great again (#2825) (@ChrisRackauckas)

v9.20.0

ModelingToolkit v9.20.0

Diff since v9.19.0

Merged pull requests:

• fix: fix observed function generation for systems with inputs (#2795) (@AayushSabharwal)
• feat: support inplace observed (#2797) (@AayushSabharwal)
• Add conservative kwarg in structural_transformation (#2805) (@YingboMa)
• fix: error properly on missing parameter values (#2807) (@AayushSabharwal)
• Refactor: Migrate from deprecated unsorted_arguments to arguments (#2816) (@bowenszhu)

Closed issues:

• build_explicit_observed_function no longer handles inputs correctly (#2794)

v9.19.0

ModelingToolkit v9.19.0

Diff since v9.18.1

Merged pull requests:

• Fix specialize overdetemined system in tearing (#2803) (@YingboMa)

Closed issues:

• Niche case of plotsol; idxs = [...]) fails (#2778)

v9.18.1

ModelingToolkit v9.18.1

Diff since v9.18.0

Merged pull requests:

• Remove componentarrays (#2800) (@ChrisRackauckas)
• Use NAMESPACE_SEPARATOR (#2801) (@YingboMa)
• Revert "Bye bye ₊, use var symbols with ." (#2802) (@YingboMa)

v9.18.0

ModelingToolkit v9.18.0

Diff since v9.17.1

Merged pull requests:

• refactor: directly solve initialization problem in linearization_function (#2762) (@AayushSabharwal)
• Better over-determined tearing (#2793) (@YingboMa)
• refactor: use common implementation of observedfun (#2796) (@AayushSabharwal)
• Bye bye ₊, use var symbols with . (#2798) (@ChrisRackauckas)

Closed issues:

• providing updated op to linearization_function has no effect (#2784)
• Initialization is incomplete without a u0, despite passing guesses (#2788)