v9.43.0

ModelingToolkit v9.43.0

Diff since v9.42.0

Merged pull requests:

• Fix structural simplification of non-1-indexed variable arrays (#2671) (@hersle)
• Clean up generate_initializesystem() (#3051) (@hersle)
• Relax type constraints to allow callable parameters in pdeps (#3079) (@SebastianM-C)
• feat: improve error message when system contains array equations (#3081) (@AayushSabharwal)
• move symbolic details to Symbolics docs (#3095) (@ArnoStrouwen)
• Allow arrays in MTKParameters pullback (#3100) (@DhairyaLGandhi)

Closed issues:

• Symbolic-array system bug in counting equations and variables (#2597)
• Structural simplification fails on non-1-indexed variable array (#2670)
• Error when setting structural parameter to define Symbolic arrays in connectors (#3058)
• Providing parameter override errors with "Initialization expression currently not supported" (#3087)
• ODE system that solved in 9.32 does error in 9.42 (#3096)
• ODE system that solved before does error in 9.42 as Overdetermined, Rank Deficient Matrix (#3097)

v9.42.0

ModelingToolkit v9.42.0

Diff since v9.41.0

Merged pull requests:

• feat: support observed function generation for DDEs (#3053) (@AayushSabharwal)
• feat: allow users to set array length via args in @mtkmodel (#3055) (@ven-k)
• fix: check scope when discovering variables from equations (#3072) (@AayushSabharwal)
• test: do not mark inversemodel tests as broken (#3073) (@AayushSabharwal)
• Fix duplicate text in documentation (#3080) (@cstjean)
• CompatHelper: bump compat for DiffEqCallbacks to 4, (keep existing compat) (#3082) (@github-actions[bot])
• Start rewriting programmatically generating systems docs (#3085) (@ArnoStrouwen)
• fix: promote resid_prototype using tunables (#3090) (@AayushSabharwal)
• Revert "feat: allow users to set array length via args in @mtkmodel" (#3092) (@YingboMa)

Closed issues:

• Better initial condition handling for dummy derivatives (#1830)
• Lacking Documentation for using DynamicQuantities (Unitful is still used in dev docs) (#2462)
• Symbolic arrays: NameState has no field symbolify (#2720)
• HTML for arrays of underscored-parameters is broken (#3052)
• Add ModelingToolkit.getdefault to public API (#3071)
• structural_simplify for io system can lead to input derivatives in RHS (#3078)

v9.41.0

ModelingToolkit v9.41.0

Diff since v9.40.1

Merged pull requests:

• feat: add reorder_dimension_by_tunables!, ensure tunable_parameters is correctly ordered (#3069) (@AayushSabharwal)
• fix: allow accessing parameter dependencies via Symbol names (#3070) (@AayushSabharwal)

Closed issues:

• DAE solve fail with symbolic registered functions in the ODEProblem. (#2860)
• Dependent parameters can't be accessed by getp(prob, ::Symbol) (#3062)

v9.40.1

ModelingToolkit v9.40.1

Diff since v9.40.0

Merged pull requests:

• feat: support callable parameters (#2995) (@AayushSabharwal)
• fix: handle nothing passed as u0 to ODEProblem (#3060) (@AayushSabharwal)

Closed issues:

• Support for callable parameters in IndexCache (#2910)
• Clarify DomainConnector error message (#3064)

v9.40.0

ModelingToolkit v9.40.0

Diff since v9.39.1

Merged pull requests:

• fix: fix missing unwrap in build_explicit_observed_function (#3040) (@AayushSabharwal)
• feat: add adjoint for remake_buffer (#3042) (@AayushSabharwal)
• Respect D(x)-like guesses (#3050) (@hersle)

Closed issues:

• Precise execution order of multiple discrete affect (#2745)
• discrete event error for DAE system (#3043)
• solve fails with InitialFailure : overdetermined system (#3047)
• D(x)-like guesses are not respected during initialization (#3049)

v9.39.1

ModelingToolkit v9.39.1

Diff since v9.39.0

Merged pull requests:

• We cannot fold unitful constants (#3036) (@YingboMa)
• Fix test setup (#3038) (@ChrisRackauckas)
• Remove incidence matrix from system show (#3039) (@ChrisRackauckas)
• Tolerate empty equations and uneven matching (#3041) (@YingboMa)

Closed issues:

• Weird results trying to simulate an RC circuit with AC power source (#1152)
• Incidence matrix structural_simplify (#2178)
• Parameter identifiability example from docs fails (#2881)
• incorrect units in observed equations (#2988)

v9.39.0

ModelingToolkit v9.39.0

Diff since v9.38.0

Merged pull requests:

• Move labelledarrays to extension testing (#3031) (@ChrisRackauckas)
• Run initialization on ODEs with superset initial conditions (#3032) (@AayushSabharwal)
• Add unit aware diff2term (#3034) (@YingboMa)
• Throw an error if structural simplification is applied twice (take 2) (#3035) (@YingboMa)

Closed issues:

• Inconsistency for how to give intiial conditions to DAEs with higher order derivatives. (#2619)
• Variables introduced during simplification of 2nd order to first order dont have the correct units. (#2959)
• Array variable units (#3009)

v9.38.0

ModelingToolkit v9.38.0

Diff since v9.37.1

Merged pull requests:

• Throw an error if structural simplification is applied twice (#3027) (@ChrisRackauckas)

Closed issues:

• repeated application of structural_simplify leads to error (#3012)

v9.37.1

ModelingToolkit v9.37.1

Diff since v9.37.0

Merged pull requests:

• fix: fix missing MTKParameters handling in linearize (#3006) (@AayushSabharwal)
• Dispatch for symbolic array units (#3015) (@aml5600)
• fix: appropriate error msg for invalid @defaults (#3022) (@ven-k)
• Override defaults when setting initial conditions with mapped unknowns(sys) (#3028) (@hersle)
• Handle dummy derivatives and more in initialize_equations (#3030) (@ChrisRackauckas)

Closed issues:

• MTK & linearization -- MTKParameters access out of bounds (#2941)
• Initial conditions set by mapping unknowns(sys) do not override defaults (#3025)
• Cannot initialize system with D(x)-like initialization equations (#3029)

v9.37.0

ModelingToolkit v9.37.0

Diff since v9.36.0

Merged pull requests:

• feat: update to new remake_buffer signature (#3020) (@AayushSabharwal)
• Make has_time_domain and get_time_domain more generic (#3026) (@YingboMa)

Closed issues:

• Building ODEProblem From ODESystem Causes AutoDiff To Fail (#2856)
• remake is broken with Bool parameters (#2866)
• BifurcationProblem drops observed variables from ODESystem (#2889)
• connect can lead to wrong flow equations (#3008)
• Simple example of structural_simplify giving ExtraVariablesSystemException (#3021)