midpoint of interval

midpoint.jl

"""midpoint of the interval [a,b]"""
function midpoint(a::Float64, b::Float64)
    #= Based on F. Goualard. 2014, Table VII
    DOI: 10.1145/2493882 =#

    if !(a ≤ b)
        return NaN
    elseif a == -Inf
        if b == Inf
            return 0.
        else
            return nextfloat(-Inf)
        end
    elseif b == Inf
        return prevfloat(Inf)
    end
    
    mid = 0.5*(a + b)
    if isfinite(mid)
        return mid
    else
        return 0.5 * a + 0.5 * b
    end
end