this is my code

```
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

```
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!