on-manifold covariance estimation

[dehann]

upgrade this:

IncrementalInference.jl/src/ApproxConv.jl

Line 156 in 7f45f63

function calcVariableCovarianceBasic(arr::AbstractMatrix)

[Affie]

I didn't realize there was an issue on this one, here is what i have so far: 5adf2f3

source https://hal.inria.fr/inria-00614994/PDF/Pennec.JMIV06.pdf

[Affie]

Just adding as a breadcrumb:

# To replace calcCovarianceBasic
function calcStdBasic(vartype::InferenceVariable, ptsArr::Vector{P}) where P
    σ = std(getManifold(vartype), ptsArr)

    #if no std yet, set to 1
    msst = 1e-10 < σ ? σ : 1.0
    return msst
end