refactor: use default t and D from MTKv9

Author: AayushSabharwal

docs/src/connectors/connections.md

@@ -90,10 +90,9 @@ As can be seen, this will give a 1 equation model matching our energy dissipatio
 
 ```@example connections
 using ModelingToolkitStandardLibrary.Electrical, ModelingToolkit, DifferentialEquations
+using ModelingToolkit: t, D
 using Plots
 
-@parameters t
-
 @named resistor = Resistor(R = 1)
 @named capacitor = Capacitor(C = 1)
 @named ground = Ground()

docs/src/tutorials/custom_component.md

@@ -8,6 +8,7 @@ First, we need to make some imports.
 
 ```@example components
 using ModelingToolkit
+using ModelingToolkit: t_nounits as t
 using ModelingToolkitStandardLibrary.Electrical
 using ModelingToolkitStandardLibrary.Electrical: OnePort
 using OrdinaryDiffEq
@@ -35,8 +36,6 @@ end NonlinearResistor;
 this can almost be directly translated to the syntax of `ModelingToolkit`.
 
 ```@example components
-@parameters t
-
 function NonlinearResistor(; name, Ga, Gb, Ve)
     @named oneport = OnePort()
     @unpack v, i = oneport

docs/src/tutorials/dc_motor_pi.md

@@ -14,14 +14,13 @@ First, the needed packages are imported and the parameters of the model defined.
 
 ```@example dc_motor_pi
 using ModelingToolkit
+using ModelingToolkit: t
 using ModelingToolkitStandardLibrary.Electrical
 using ModelingToolkitStandardLibrary.Mechanical.Rotational
 using ModelingToolkitStandardLibrary.Blocks
 using OrdinaryDiffEq
 using Plots
 
-@parameters t
-
 R = 0.5 # [Ohm] armature resistance
 L = 4.5e-3 # [H] armature inductance
 k = 0.5 # [N.m/A] motor constant

docs/src/tutorials/input_component.md

@@ -14,13 +14,11 @@ The `ModelingToolkitStandardLibrary.Blocks.TimeVaryingFunction` component is eas
 
 ```julia
 using ModelingToolkit
+using ModelingToolkit: t, D
 using ModelingToolkitStandardLibrary.Blocks
 using DataInterpolations
 using OrdinaryDiffEq
 
-@parameters t
-D = Differential(t)
-
 function System(f; name)
     src = TimeVaryingFunction(f)
 

docs/src/tutorials/thermal_model.md

@@ -8,8 +8,7 @@ from dividing the total initial energy in the system by the sum of the heat capa
 
 ```@example
 using ModelingToolkitStandardLibrary.Thermal, ModelingToolkit, OrdinaryDiffEq, Plots
-
-@parameters t
+using ModelingToolkit: t
 
 C1 = 15
 C2 = 15

src/Blocks/Blocks.jl

@@ -5,10 +5,7 @@ module Blocks
 using ModelingToolkit, Symbolics
 import IfElse: ifelse
 import ..@symcheck
-using ModelingToolkit: getdefault
-
-@parameters t
-D = Differential(t)
+using ModelingToolkit: getdefault, t, D
 
 export RealInput, RealOutput, SISO
 include("utils.jl")

src/Blocks/continuous.jl

@@ -542,7 +542,7 @@ linearized around the operating point `x₀, u₀`, we have `y0, u0 = h(x₀, u
     ]
     # pars = @parameters A=A B=B C=C D=D # This is buggy
     eqs = [ # FIXME: if array equations work
-        [Differential(t)(x[i]) ~ sum(A[i, k] * x[k] for k in 1:nx) +
+        [D(x[i]) ~ sum(A[i, k] * x[k] for k in 1:nx) +
                                  sum(B[i, j] * (input.u[j] - u0[j]) for j in 1:nu)
          for i in 1:nx]..., # cannot use D here
         [output.u[j] ~ sum(C[j, i] * x[i] for i in 1:nx) +

src/Electrical/Electrical.jl

@@ -5,13 +5,11 @@ This library contains electrical components to build up analog circuits.
 module Electrical
 
 using ModelingToolkit, Symbolics, IfElse
+using ModelingToolkit: t, D
 using ..Thermal: HeatPort
 using ..Mechanical.Rotational: Flange, Support
 using ..Blocks: RealInput, RealOutput
 
-@parameters t
-D = Differential(t)
-
 export Pin, OnePort
 include("utils.jl")
 

src/Hydraulic/IsothermalCompressible/IsothermalCompressible.jl

@@ -4,15 +4,13 @@ Library to model iso-thermal compressible liquid fluid flow
 module IsothermalCompressible
 
 using ModelingToolkit, Symbolics
+using ModelingToolkit: t, D
 
 using ...Blocks: RealInput, RealOutput
 using ...Mechanical.Translational: MechanicalPort, Mass
 
 using IfElse: ifelse
 
-@parameters t
-D = Differential(t)
-
 export HydraulicPort, HydraulicFluid
 include("utils.jl")
 

src/Magnetic/FluxTubes/FluxTubes.jl

@@ -1,10 +1,8 @@
 module FluxTubes
 using ModelingToolkit
+using ModelingToolkit: t, D
 using ...Electrical: Pin
 
-@parameters t
-D = Differential(t)
-
 export PositiveMagneticPort, NegativeMagneticPort, TwoPort
 include("utils.jl")
 

src/Mechanical/MultiBody2D/MultiBody2D.jl

@@ -1,10 +1,9 @@
 module MultiBody2D
 
 using ModelingToolkit, Symbolics, IfElse
-using ..TranslationalPosition
+using ModelingToolkit: t, D
 
-@parameters t
-D = Differential(t)
+using ..TranslationalPosition
 
 export Link
 include("components.jl")

src/Mechanical/Rotational/Rotational.jl

@@ -4,12 +4,11 @@ Library to model 1-dimensional, rotational mechanical systems
 module Rotational
 
 using ModelingToolkit, Symbolics, IfElse
+using ModelingToolkit: t, D
+
 using ...Blocks: RealInput, RealOutput
 import ...@symcheck
 
-@parameters t
-D = Differential(t)
-
 export Flange, Support
 include("utils.jl")
 

src/Mechanical/Translational/Translational.jl

@@ -4,14 +4,11 @@ Library to model 1-dimensional, translational mechanical systems
 module Translational
 
 using ModelingToolkit, Symbolics
-using ModelingToolkit: getdefault
+using ModelingToolkit: getdefault, t, D
 
 using ModelingToolkitStandardLibrary.Blocks: RealInput, RealOutput
 using IfElse: ifelse
 
-@parameters t
-D = Differential(t)
-
 export MechanicalPort
 include("utils.jl")
 

src/Mechanical/TranslationalModelica/TranslationalModelica.jl

@@ -4,10 +4,9 @@ Library to model 1-dimensional, translational mechanical components.
 module TranslationalModelica
 
 using ModelingToolkit, Symbolics, IfElse
-using ...Blocks: RealInput, RealOutput
+using ModelingToolkit: t, D
 
-@parameters t
-D = Differential(t)
+using ...Blocks: RealInput, RealOutput
 
 export Flange
 include("utils.jl")

src/Mechanical/TranslationalPosition/TranslationalPosition.jl

@@ -4,10 +4,9 @@ Library to model 1-dimensional, translational mechanical components.
 module TranslationalPosition
 
 using ModelingToolkit, Symbolics, IfElse
-using ...Blocks: RealInput, RealOutput
+using ModelingToolkit: t, D
 
-@parameters t
-D = Differential(t)
+using ...Blocks: RealInput, RealOutput
 
 export Flange
 include("utils.jl")

src/Thermal/Thermal.jl

@@ -3,10 +3,9 @@ Library of thermal system components to model heat transfer.
 """
 module Thermal
 using ModelingToolkit, Symbolics, IfElse
-using ...Blocks: RealInput, RealOutput
+using ModelingToolkit: t, D
 
-@parameters t
-D = Differential(t)
+using ...Blocks: RealInput, RealOutput
 
 export HeatPort, Element1D
 include("utils.jl")

test/Blocks/continuous.jl

@@ -1,10 +1,9 @@
 using ModelingToolkit, ModelingToolkitStandardLibrary, OrdinaryDiffEq
+using ModelingToolkit: t
 using ModelingToolkitStandardLibrary.Blocks
 using OrdinaryDiffEq: ReturnCode.Success
 using Test
 
-@parameters t
-
 #=
 Testing strategy:
 The general strategy is to test systems using simple inputs where the solution
@@ -137,7 +136,6 @@ Second order demo plant
 @component function Plant(; name, x = zeros(2))
     @named input = RealInput()
     @named output = RealOutput()
-    D = Differential(t)
     sts = @variables x1(t)=x[1] x2(t)=x[2]
     eqs = [D(x1) ~ x2
         D(x2) ~ -x1 - 0.5 * x2 + input.u

test/Blocks/math.jl

@@ -1,11 +1,9 @@
 using ModelingToolkitStandardLibrary.Blocks
 using ModelingToolkit, OrdinaryDiffEq, Test
 using ModelingToolkitStandardLibrary.Blocks: _clamp, _dead_zone
-using ModelingToolkit: inputs, unbound_inputs, bound_inputs
+using ModelingToolkit: inputs, unbound_inputs, bound_inputs, t
 using OrdinaryDiffEq: ReturnCode.Success
 
-@parameters t
-
 @testset "Gain" begin
     @named c = Constant(; k = 1)
     @named gain = Gain(; k = 1)

test/Blocks/nonlinear.jl

@@ -1,10 +1,9 @@
 using ModelingToolkit, OrdinaryDiffEq
+using ModelingToolkit: t
 using ModelingToolkitStandardLibrary.Blocks
 using ModelingToolkitStandardLibrary.Blocks: _clamp, _dead_zone
 using OrdinaryDiffEq: ReturnCode.Success
 
-@parameters t
-
 @testset "Limiter" begin
     @testset "Constant" begin
         @named c = Constant(; k = 1)

test/Blocks/sources.jl

@@ -1,13 +1,11 @@
 using ModelingToolkit, ModelingToolkitStandardLibrary, OrdinaryDiffEq
+using ModelingToolkit: t, D
 using ModelingToolkitStandardLibrary.Blocks
 using ModelingToolkitStandardLibrary.Blocks: smooth_sin, smooth_cos, smooth_damped_sin,
     smooth_square, smooth_step, smooth_ramp,
     smooth_triangular, triangular, square
 using OrdinaryDiffEq: ReturnCode.Success
 
-@parameters t
-D = Differential(t)
-
 @testset "Constant" begin
     @named src = Constant(k = 2)
     @named int = Integrator()

test/Blocks/test_analysis_points.jl

@@ -2,7 +2,7 @@ using Test, LinearAlgebra
 using ModelingToolkit
 using ModelingToolkitStandardLibrary.Blocks
 using OrdinaryDiffEq
-using ModelingToolkit: get_eqs, vars, @set!, get_iv
+using ModelingToolkit: get_eqs, vars, @set!, get_iv, t
 using ControlSystemsBase
 
 @named P = FirstOrder(k = 1, T = 1)
@@ -231,7 +231,6 @@ Si = ss(matrices...)
 @test tf(So) ≈ tf(Si)
 
 ## A simple multi-level system with loop openings
-@parameters t
 @named P_inner = FirstOrder(k = 1, T = 1)
 @named feedback = Feedback()
 @named ref = Step()

test/Electrical/analog.jl

@@ -1,4 +1,5 @@
 using ModelingToolkitStandardLibrary.Electrical, ModelingToolkit, OrdinaryDiffEq, Test
+using ModelingToolkit: t
 using ModelingToolkitStandardLibrary.Blocks: Step,
     Constant, Sine, Cosine, ExpSine, Ramp,
     Square, Triangular
@@ -7,8 +8,6 @@ using OrdinaryDiffEq: ReturnCode.Success
 
 # using Plots
 
-@parameters t
-
 @testset "sensors" begin
     @named source = Sine(offset = 1, amplitude = 10, frequency = 5)
     @named voltage = Voltage()

test/Electrical/digital.jl

@@ -4,7 +4,7 @@ using ModelingToolkitStandardLibrary.Electrical: U, X, F0, F1, Z, W, L, H, DC, U
 using ModelingToolkitStandardLibrary.Electrical: AndTable, OrTable, NotTable, XorTable
 using ModelingToolkitStandardLibrary.Electrical: get_logic_level
 using OrdinaryDiffEq: ReturnCode.Success
-
+# using ModelingToolkit: t, D
 # using ModelingToolkitStandardLibrary.Electrical: Set, Reset
 
 @testset "Logic, logic-vectors and helpers" begin
@@ -96,8 +96,6 @@ end
 
 #=
 
-@parameters t
-
 @named set1 = Set()
 @named reset1 = Reset()
 @named set2 = Set()

test/Hydraulic/isothermal_compressible.jl

@@ -1,13 +1,11 @@
 using ModelingToolkit, OrdinaryDiffEq, Test
+using ModelingToolkit: t, D
 import ModelingToolkitStandardLibrary.Hydraulic.IsothermalCompressible as IC
 import ModelingToolkitStandardLibrary.Blocks as B
 import ModelingToolkitStandardLibrary.Mechanical.Translational as T
 
 using ModelingToolkitStandardLibrary.Blocks: Parameter
 
-@parameters t
-D = Differential(t)
-
 NEWTON = NLNewton(check_div = false, always_new = true, max_iter = 100, relax = 9 // 10)
 
 @testset "Fluid Domain and Tube" begin
@@ -195,8 +193,6 @@ end
 
 @testset "Actuator System" begin
     function System(use_input, f; name)
-        @parameters t
-
         pars = @parameters begin
             p_s = 200e5
             p_r = 5e5

test/Magnetic/magnetic.jl

@@ -4,11 +4,10 @@ import ModelingToolkitStandardLibrary.Electrical
 import ModelingToolkitStandardLibrary.Blocks
 import ModelingToolkitStandardLibrary.Magnetic
 using ModelingToolkit, OrdinaryDiffEq, Test
+using ModelingToolkit: t, D
 using OrdinaryDiffEq: ReturnCode.Success
 # using Plots
 
-@parameters t
-
 @testset "Inductor" begin
     mu_air = 1
     l_air = 0.0001

test/Mechanical/multibody.jl

@@ -1,12 +1,11 @@
 using ModelingToolkit
+using ModelingToolkit: t
 using ModelingToolkitStandardLibrary.Mechanical.MultiBody2D
 using ModelingToolkitStandardLibrary.Mechanical.TranslationalPosition
 using OrdinaryDiffEq
 # using Setfield
 using Test
 
-@parameters t
-
 @named link1 = Link(; m = 1, l = 10, I = 84, g = -9.807)
 @named link2 = Link(; m = 1, l = 10, I = 84, g = -9.807, x1_0 = 10)
 @named cart = Mass(; m = 1, s = 0)

test/Mechanical/rotational.jl

@@ -1,14 +1,12 @@
 using ModelingToolkitStandardLibrary.Mechanical.Rotational,
     ModelingToolkit, OrdinaryDiffEq,
     Test
+using ModelingToolkit: t, D
 import ModelingToolkitStandardLibrary.Blocks
 using OrdinaryDiffEq: ReturnCode.Success
 
 # using Plots
 
-@parameters t
-D = Differential(t)
-
 @testset "two inertias" begin
     @named fixed = Fixed()
     @named inertia1 = Inertia(J = 2) # this one is fixed