dladgen.jl

###############################################################################
#
# Compute leaf inclination angle distribution?
#
###############################################################################
"""
    dcum(a::FT, b::FT, t::FT) where {FT<:AbstractFloat}

TODO Add function description
"""
function dcum(a::FT, b::FT, t::FT) where {FT<:AbstractFloat}
    if a >= 1
        f = 1 - cosd(t);
    else
        y    = 0;
        epsi = FT(1e-8);
        delx = 1;
        x    = 2 * deg2rad(t);
        p    = x;
        # add a iteration number (n) control to avoid presicion issues
        n    = 0;
        while (delx >= epsi) && (n<50)
            n   += 1;
            y    = a*sin(x) + b*sin(2x)/2;
            dx   = (y - x + p) / 2;
            x   += dx;
            delx = abs(dx);
        end
        f = (2*y + p) / FT(pi);
    end

    return f
end




"""
    dladgen(a::FT, b::FT, litab_bnd::Array{FT,2}) where {FT<:AbstractFloat}

TODO Calculate the freqency of WHAT?
"""
function dladgen(
            a::FT,
            b::FT,
            litab_bnd::Array{FT,2}
) where {FT<:AbstractFloat}
    @assert a + b <= 1;
    freq = similar(litab_bnd[:,1]);
    for i in eachindex(freq)
        freq[i] = dcum(a, b, litab_bnd[i,2]) - dcum(a, b, litab_bnd[i,1]);
    end

    return freq
end