# Problem defining Continuos Dynamical Systems

**URL:** <https://discourse.julialang.org/t/problem-defining-continuos-dynamical-systems/73009>\
**Category:** Modelling & Simulations\
**Tags:** question, package\
**Created:** [December 13, 2021, 7:17am UTC](https://discourse.julialang.org/t/problem-defining-continuos-dynamical-systems/73009 "2021-12-13T07:17:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![pafloxy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pafloxy/32/28694_2.png) [@pafloxy](https://discourse.julialang.org/u/pafloxy)\
**Post date:** [December 13, 2021, 7:17am UTC](https://discourse.julialang.org/t/problem-defining-continuos-dynamical-systems/73009/1 "2021-12-13T07:17:35Z")

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I am having a problem defining the Rossler system using the following way~

```nohighlight
    ##eom~~
    @inline @inbounds function rossler_eom( u, p, t)
        a = p[1]; b = p[2]; c = p[3]
        du1 = -u[2] - u[3]
        du2 = u[1] + a*u[2]
        du3 = b + (u[1] - c)*u[3]
        return SVector{3}(du1, du2, du3)
    end
    ##jacobian~~
    @inline @inbounds function rossler_jac( u, p, t)
        a ,b ,c = p
        jac = @SMatrix [0 -1 -1;
                       1 a 0;
                        (0) (0) (u[1]-c)]
        return jac
    end
    u0 = rand(3)
    parameters = [0.2, 0.2, 5.7]
    perturbation = [0,0,0]
    perturbation[p_i] = 1
    perturbed_parameters = parameters + Δp*perturbation 
    rossler_o = ContinuousDynamicalSystem(rossler_eom, u0, parameters, rossler_jac)
    rossler_p = ContinuousDynamicalSystemn(rossler_eom, u0, perturbed_parameters, rossler_jac)
    return rossler_o, rossler_p
end

```

```julia
tevolve = 50.00
time_step = 0.02
transient_time = 0
ross_o, ross_p = generate_rossler(rand(3), 0.01, 3)
tr_o = trajectory(ross_o, tevolve; Δt= time_step , Ttr= transient_time )
tr_p = trajectory(ross_p, tevolve; Δt= time_step , Ttr= transient_time )

```

returns this output

````julia
UndefVarError: ContinuousDynamicalSystemn not defined

Stacktrace:
 [1] generate_rossler(::Array{Float64,1}, ::Float64, ::Int64) at ./In[6]:28
 [2] top-level scope at In[7]:4774: ```
````

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<div class="post-metadata">

**Author:** ![JM\_Beckers](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jm_beckers/32/22482_2.png) [@JM\_Beckers](https://discourse.julialang.org/u/JM_Beckers)\
**Post date:** [December 13, 2021, 8:46am UTC](https://discourse.julialang.org/t/problem-defining-continuos-dynamical-systems/73009/2 "2021-12-13T08:46:49Z")

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Typo ?  
ContinuousDynamicalSystem **n**

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<div class="post-metadata">

**Author:** ![pafloxy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pafloxy/32/28694_2.png) [@pafloxy](https://discourse.julialang.org/u/pafloxy)\
**Post date:** [December 13, 2021, 10:47am UTC](https://discourse.julialang.org/t/problem-defining-continuos-dynamical-systems/73009/3 "2021-12-13T10:47:16Z")

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Shit!  
Thanks, man I have been scratching my head on this all this while.