AlmostBandedMatrix(bands::BandedMatrix, fill)
AlmostBandedMatrix{T}(bands, fill)
AlmostBandedMatrix(::UndefInitializer, [::Type{T} = Float64], mn::NTuple{2, Integer},
    lu::NTuple{2, Integer}, rank::Integer)
AlmostBandedMatrix{T}(::UndefInitializer, mn::NTuple{2, Integer},
    lu::NTuple{2, Integer}, rank::Integer)

An AlmostBandedMatrix is a matrix with a bands part and a fill part. For efficient operations we store the matrix as a BandedMatrix and another AbstractMatrix with an overlapping bit.

[3 3 3 2 2 2 2 ... 2 2 2]
[3 3 3 3 2 2 2 ... 2 2 2]
[0 1 1 1 1 0 0 ... 0 0 0]
[0 0 1 1 1 1 0 ... 0 0 0]
[.......................]
[.......................]
[.......................]
[0 0 0 0 0 0 0 ... 1 1 0]
[0 0 0 0 0 0 0 ... 1 1 1]

where 2's are the fill part, and 1's are the bands part, and 3's are the overlapping part.

bandpart(A::AlmostBandedMatrix)

Banded Part of the AlmostBandedMatrix.

exclusive_bandpart(A::AlmostBandedMatrix)

Banded Part of the AlmostBandedMatrix without the overlapping part.

fillpart(A::AlmostBandedMatrix)

Fill Part of the AlmostBandedMatrix.