I meet a problem for swtich __ Anyone can help?

[yanshuchang]

# 使用
using ModelingToolkit,Plots,DifferentialEquations,Optimization,...
      Plots, DifferentialEquations,LinearAlgebra, Distributions,Unitful,ModelingToolkitStandardLibrary 
using Symbolics:scalarize

using IfElse: ifelse
# 以下按照 从左到右， 从上到下 的方式写模型



@variables t

@connector function Pin(; name)
    sts = @variables begin
        v(t)                    # Potential at the pin [V]
        i(t), [connect = Flow]    # Current flowing into the pin [A]
    end
    ODESystem(Equation[], t, sts, [], name = name, defaults = Dict(v => 1.0, i => 1.0))
end


function switch(;name)

    @named   p   =  Pin()
    @named   n   =  Pin()

    #@parameters sig = m

    sts = @variables begin
        v(t)
        i(t)
    end


    eqs = [v ~ p.v - n.v
           0 ~ p.i + n.i
           i ~ p.i]


    sc = [10] => [i ~ 0]

    

    injection = t == 10.0 => [i ~ 0]
    modelll=compose(ODESystem(eqs, t, sts, []; name=name, discrete_events = injection), p, n)
end



@named rm  =  ModelingToolkitStandardLibrary.Electrical.Resistor(R = 4)                # 电阻模块， 不要轻易加 name。
@named lm  =  ModelingToolkitStandardLibrary.Electrical.Inductor(L = 1)                 # 电感模块， 不要轻易加 name。
#@named sm  =  sdc(vf = Vf)                                                               # 电压源模块

    # 1. 测试一下模块的入口还有出口

@named input_v = ModelingToolkitStandardLibrary.Blocks.Constant(k=4)
@named input_pin = ModelingToolkitStandardLibrary.Electrical.Voltage()
@named g = ModelingToolkitStandardLibrary.Electrical.Ground()
@named sw = switch()
  
eqs = [
        connect(input_pin.V, input_v.output)
        connect(input_pin.p, rm.p)
        connect(rm.n, sw.p)
        connect(sw.n, g.g)
        connect(g.g, input_pin.n)
    ]

@named _mol = ODESystem(eqs, t)

@named  mol = compose(_mol,  [input_v, g, input_pin, rm, sw])


sys = structural_simplify(mol)
prob = ODEProblem(sys, [], (0., 20.))
sol = solve(prob, Rosenbrock23())

[yanshuchang]

KeyError: key sw₊i(t) not found

[yanshuchang]

who can see where is wrong?

[yanshuchang]

# 使用
using ModelingToolkit,Plots,DifferentialEquations,Optimization,...
      Plots, DifferentialEquations,LinearAlgebra, Distributions,Unitful,ModelingToolkitStandardLibrary 
using Symbolics:scalarize

using IfElse: ifelse
# 以下按照 从左到右， 从上到下 的方式写模型



@variables t

@connector function Pin(; name)
    sts = @variables begin
        v(t)                    # Potential at the pin [V]
        i(t), [connect = Flow]    # Current flowing into the pin [A]
    end
    ODESystem(Equation[], t, sts, [], name = name, defaults = Dict(v => 1.0, i => 1.0))
end



function OnePort(; name, v_start = 0.0, i_start = 0.0)
    @named p = Pin()
    @named n = Pin()
    sts = @variables begin
        v(t) = v_start
        i(t) = i_start
    end
    eqs = [v ~ p.v - n.v
           0 ~ p.i + n.i
           i ~ p.i]
    return compose(ODESystem(eqs, t, sts, []; name = name), p, n)
end




@named rm  =  ModelingToolkitStandardLibrary.Electrical.Resistor(R = 4)                # 电阻模块， 不要轻易加 name。
@named lm  =  ModelingToolkitStandardLibrary.Electrical.Inductor(L = 1)                 # 电感模块， 不要轻易加 name。
#@named sm  =  sdc(vf = Vf)                                                               # 电压源模块

    # 1. 测试一下模块的入口还有出口

@named input_v = ModelingToolkitStandardLibrary.Blocks.Constant(k=4)
@named input_pin = ModelingToolkitStandardLibrary.Electrical.Voltage()
@named g = ModelingToolkitStandardLibrary.Electrical.Ground()
@named sw = OnePort(v_start = 0.0, i_start = 0.0)
  
eqs = [
        connect(input_pin.V, input_v.output)
        connect(input_pin.p, rm.p)
        connect(rm.n, sw.p)
        connect(sw.n, g.g)
        connect(g.g, input_pin.n)
    ]

@named _mol = ODESystem(eqs, t)

@named  mol = compose(_mol,  [input_v, g, input_pin, rm, sw])


sys = structural_simplify(mol)
prob = ODEProblem(sys, [], (0., 20.))
sol = solve(prob, Rosenbrock23())

[yanshuchang]

In fact, I change the switch function to a one-port function ( which can be seen as a wire with no resistance in electric, it still reports errors. And thus, I think maybe there are something should be revised in MTK to make the se things work.

[yanshuchang]

# 使用
using ModelingToolkit,Plots,DifferentialEquations,Optimization,...
      Plots, DifferentialEquations,LinearAlgebra, Distributions,Unitful,ModelingToolkitStandardLibrary 
using Symbolics:scalarize

using IfElse: ifelse
# 以下按照 从左到右， 从上到下 的方式写模型



@variables t

@connector function Pin(; name)
    sts = @variables begin
        v(t)                    # Potential at the pin [V]
        i(t), [connect = Flow]    # Current flowing into the pin [A]
    end
    ODESystem(Equation[], t, sts, [], name = name, defaults = Dict(v => 1.0, i => 1.0))
end



function OOnePort(; name, v_start = 0.0, i_start = 0.0)
    @named p = Pin()
    @named n = Pin()
    sts = @variables begin
        v(t) = v_start
        i(t) = i_start
    end
    eqs = [0 ~ p.v - n.v
           0 ~ p.i + n.i]

    injection = t == 10.0 => [p.i ~ 0]

    return compose(ODESystem(eqs, t, [], []; name=name, discrete_events = injection), p, n)

    #return compose(ODESystem(eqs, t, sts, []; name = name), p, n)
end




@named rm  =  ModelingToolkitStandardLibrary.Electrical.Resistor(R = 4)                # 电阻模块， 不要轻易加 name。
@named lm  =  ModelingToolkitStandardLibrary.Electrical.Inductor(L = 1)                 # 电感模块， 不要轻易加 name。
#@named sm  =  sdc(vf = Vf)                                                               # 电压源模块

    # 1. 测试一下模块的入口还有出口

@named input_v = ModelingToolkitStandardLibrary.Blocks.Constant(k=4)
@named input_pin = ModelingToolkitStandardLibrary.Electrical.Voltage()
@named g = ModelingToolkitStandardLibrary.Electrical.Ground()
@named sw = OOnePort(v_start = 0.0, i_start = 0.0)
  
eqs = [
        connect(input_pin.V, input_v.output)
        connect(input_pin.p, rm.p)
        connect(rm.n, sw.p)
        connect(sw.n, g.g)
        connect(g.g, input_pin.n)
    ]

@named _mol = ODESystem(eqs, t)

@named  mol = compose(_mol,  [input_v, g, input_pin, rm, sw])


sys = structural_simplify(mol)
prob = ODEProblem(sys, [], (0., 20.))
sol = solve(prob, Rosenbrock23())
plot(sol(0:0.001:1, idxs = rm.i),label='I')

[yanshuchang]

""KeyError: key sw₊p₊i(t) not found"" Another example attached here but it still reports errors.

[yanshuchang]

Finally, I decided to give up MTK, its programming is so complicated and the support is not timely. Even if I have the ambition to use and further extend it by industrial application, but my project do not allow me to do so. So pity a story.

[ChrisRackauckas]

Alright, we'll keep improving the documentation and errors but as stated earlier to you, this package is still very much in its primacy and so there are some training issues that we know and cannot handle the burden of right now. Take care!