# Question about LPVSpectral

**URL:** <https://discourse.julialang.org/t/question-about-lpvspectral/44615>\
**Category:** General Usage\
**Tags:** question\
**Created:** [August 9, 2020, 2:03pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615 "2020-08-09T14:03:13Z")\
**Posts on this page:** 16\
**Page:** 1

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**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 9, 2020, 2:03pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/1 "2020-08-09T14:03:13Z")

</div>

this is my code

```julia
using LPVSpectral, Plots
a=convert(Vector{Float64},rand(20))
λ = 0.02 # Regularization parameter
λs = 1 # Regularization parameter group-lasso
normal = true # Use normalized basis functions
Nv = 50 # Number of basis functions
 x = sort(10rand(20))
  v = range(0, stop=1, length=20) 
se = ls_spectral_lpv(a,X,V,w_test,Nv; λ = λ, normalize = normal)

```

this is the errdr:  
LoadError: UndefVarError: warn not defined  
Stacktrace:  
[1] ls\_spectral\_lpv(::Array{Float64,1}, ::Array{Float64,1}, ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::StepRangeLen{Float64,Base.TwicePrecision{Float64},Base.TwicePrecision{Float64}}, ::Int64; λ::Float64, coulomb::Bool, normalize::Bool) at C:\Users\27990.juliapro\JuliaPro\_v1.4.2-1\packages\LPVSpectral\7XqRc\src\lsfft.jl:256  
[2] top-level scope at untitled-9f246b91b79fbac6d315ccc2dda483e2:57  
in expression starting at untitled-9f246b91b79fbac6d315ccc2dda483e2:57  
this is the original code

```julia
    params = real_complex_bs(A,Y,λ)
    real_params = [real.(params); imag.(params)]
    AA = [real.(A) imag.(A)]
    e = AA*real_params-Y
    Σ = var(e)*inv(AA'AA + λ*I)
    fva = 1-var(e)/var(Y)
    fva < 0.9 && warn("Fraction of variance explained = $(fva)")
    SpectralExt(Y, X, V, w, Nv, λ, coulomb, normalize, params, Σ)

```

Is the “warn” version of the original code no longer supported?thanks!

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 9, 2020, 2:04pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/2 "2020-08-09T14:04:45Z")

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@baggepinnen

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<div class="post-metadata">

**Author:** ![baggepinnen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/baggepinnen/32/693_2.png) [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Post date:** [August 9, 2020, 2:52pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/3 "2020-08-09T14:52:13Z")

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Yeah it looks like the old api for calling warn. You can simply change it to `@warn` and either open an issue or a PR and I’ll merge it as soon as possible.

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 9, 2020, 2:54pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/4 "2020-08-09T14:54:11Z")

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ok,thanks!

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<div class="post-metadata">

**Author:** ![baggepinnen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/baggepinnen/32/693_2.png) [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Post date:** [August 9, 2020, 2:55pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/5 "2020-08-09T14:55:33Z")

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Made the change here [https://github.com/baggepinnen/LPVSpectral.jl/commit/24bf834e0a9b2db81716890a58026e18a0278e46](https://github.com/baggepinnen/LPVSpectral.jl/commit/24bf834e0a9b2db81716890a58026e18a0278e46)  
New version will be out soon. Thanks for the report!

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 9, 2020, 2:56pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/6 "2020-08-09T14:56:36Z")

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Thank you for your answer！！

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 9, 2020, 3:00pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/7 "2020-08-09T15:00:39Z")

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Hello!I have some other questions to ask you. I have sent you an email. Please help me when you are free.Sorry to trouble you!Thank you!!

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<div class="post-metadata">

**Author:** ![baggepinnen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/baggepinnen/32/693_2.png) [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Post date:** [August 9, 2020, 4:06pm UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/8 "2020-08-09T16:06:00Z")

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No worries, I’ll answer you within a day or so!

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 10, 2020, 4:55am UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/9 "2020-08-10T04:55:39Z")

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thankS!!

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 10, 2020, 7:05am UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/10 "2020-08-10T07:05:54Z")

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Another question is, how do I assign X, Vand other parameters in `se = ls_spectral_lpv(a,X,V,w_test,Nv; λ = λ, normalize = normal)`?thanks!

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<div class="post-metadata">

**Author:** ![baggepinnen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/baggepinnen/32/693_2.png) [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Post date:** [August 10, 2020, 7:28am UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/11 "2020-08-10T07:28:18Z")

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What analysis are you trying to perform? If you describe your data, I can map it to the arguments for you, provided that the LPV spectral estimation method is indeed the appropriate method to use.

You also find a description of the arguments in the docstring  
[https://github.com/baggepinnen/LPVSpectral.jl/blob/24bf834e0a9b2db81716890a58026e18a0278e46/src/lsfft.jl#L226](https://github.com/baggepinnen/LPVSpectral.jl/blob/24bf834e0a9b2db81716890a58026e18a0278e46/src/lsfft.jl#L226)

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 10, 2020, 7:41am UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/12 "2020-08-10T07:41:52Z")

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My data is every 15 minutes.I want LPVSpectral of the weekly data curve.(That is, to analyze the curve composed of 672 points).I don’t understand what these parameters(sample locations、scheduling signal、frequency vector.etc) mean,Forgive me for not being professional 😣  
Thank you very much!

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<div class="post-metadata">

**Author:** ![baggepinnen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/baggepinnen/32/693_2.png) [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Post date:** [August 10, 2020, 7:57am UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/13 "2020-08-10T07:57:05Z")

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Are you aware of what analysis the LPV method is performing? If not, it’s probably not the right method to use and you should consider a standard spectral estimate, like `ls_spectral`. In any case,  
Y is the signal you want to analyse, X are the time points at which it is sampled, V is an auxiliary signal that the spectrum of Y depends on. If you don’t have such an auxiliary signal, you should consider standard spectral estimation instead.

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 10, 2020, 8:25am UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/14 "2020-08-10T08:25:27Z")

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Does the auxiliary signal refer to an auxiliary signal?Can I take the signal formed by the average of each moment as an auxiliary signal?

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<div class="post-metadata">

**Author:** ![baggepinnen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/baggepinnen/32/693_2.png) [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Post date:** [August 10, 2020, 9:22am UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/15 "2020-08-10T09:22:26Z")

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> [@abcde](#):
>
> Does the auxiliary signal refer to an auxiliary signal?

???

I don’t think this method is right for you. Try `ls_spectral` instead.

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<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [August 10, 2020, 9:24am UTC](https://discourse.julialang.org/t/question-about-lpvspectral/44615/16 "2020-08-10T09:24:11Z")

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thanks! i will try it