# Problem using \`\`\`lyapunov spectrum\`\`\`

**URL:** <https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224>\
**Category:** Numerics\
**Tags:** package\
**Created:** [January 26, 2022, 12:05pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224 "2022-01-26T12:05:13Z")\
**Posts on this page:** 8\
**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:** [January 26, 2022, 12:05pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224/1 "2022-01-26T12:05:13Z")

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![image](https://global.discourse-cdn.com/julialang/original/3X/1/5/15bc9641e5de0b7080322f25d84c56ad5690c73d.png)  
the follwing code cannot recognise the `lyapunovspectrum` function.  
`lyapunovspectrum(ds_3, 10 ; Ttr= 10.00)`  
Can anyone point out the problem here ?

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**Author:** ![josuagrw](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/josuagrw/32/1015_2.png) [@josuagrw](https://discourse.julialang.org/u/josuagrw)\
**Post date:** [January 26, 2022, 12:08pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224/2 "2022-01-26T12:08:22Z")

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Please provide a bit more information; which packages are you using, etc

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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:** [January 26, 2022, 12:12pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224/3 "2022-01-26T12:12:41Z")

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Mainly it is the `DynamicalSystem.jl` that I’m using for this code. The problem is whatever the function `lyapuonvspectrum` is supposed to do according to [Lyapunov Exponents · DynamicalSystems.jl](https://juliadynamics.github.io/DynamicalSystems.jl/latest/chaos/lyapunovs/#Lyapunov-Spectrumfunction)  
is rahter being done by the function `lyapunovs`, however their website is showing something different.

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**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [January 26, 2022, 12:14pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224/4 "2022-01-26T12:14:40Z")

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This appears to be from the `ChaosTools` package, did you do `using ChaosTools`?

This works for me:

```julia
julia> using ChaosTools

julia> lyapunovspectrum
lyapunovspectrum (generic function with 8 methods)

```

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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:** [January 26, 2022, 12:31pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224/5 "2022-01-26T12:31:45Z")

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Nope I did not ! But isn’t it supposed to be imported already with `DynamicalSystems.jl` ?

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**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [January 26, 2022, 1:22pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224/6 "2022-01-26T13:22:07Z")

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Yes, correct. In a fresh Julia session (without `using ChaosTools`):

```julia
julia> using DynamicalSystems

julia> lyapunovspectrum
lyapunovspectrum (generic function with 8 methods)

```

`DynamicalSystems` reexports `ChaosTools`, see here:

[https://github.com/JuliaDynamics/DynamicalSystems.jl/blob/master/src/DynamicalSystems.jl#L15](https://github.com/JuliaDynamics/DynamicalSystems.jl/blob/master/src/DynamicalSystems.jl#L15)

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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:** [January 26, 2022, 1:23pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224/7 "2022-01-26T13:23:49Z")

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Well then what exactly went wrong ?

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<div class="post-metadata">

**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [January 26, 2022, 1:25pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224/8 "2022-01-26T13:25:40Z")

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I don’t know, you tell me? You’ve just posted a screnshoot where `lyapunovspectrum` isn’t defined, which can occur in loads of ways (e.g. not loading any packages). If you want others to be able to figure out what went wrong in your specific case, you should post an MWE.