using LinearAlgebra, Plots, Statistics

include("../11-3/readyalefaces_to_tensor.jl")
function interactiverec(F, iterstop::Union{Nothing, Integer}=nothing)
    # given a 243x320 image F, displays it as sum of components
    stdsize = (243, 320)
    
    (X, _) = readyalefaces_to_tensor()

    X = reshape(X, (prod(stdsize), Integer(prod(size(X)) / prod(stdsize))))

    avg = mean(X, dims=2)
    Xs = X .- avg
    (U,S,V) = svd(X)

    h = Plots.heatmap(reshape(avg, stdsize), yflip=true)
    display(h)

    if iterstop == nothing
        upto = size(U, 2)
    else
        upto = min(size(U, 2), iterstop)
    end

    # no fancy slider, not enough time
    for d ∈ 0:upto
        h = heatmap(reshape(avg .+ U[:, 1:d] * U[:, 1:d]' * F, stdsize), yflip=true)
        IJulia.clear_output(true)
        display(h)
    end
end