Coordinates

struct Cylindrical{T<:Real, A<:Real}

3-dimensional cylindrical coordinates, denoted by $(s, φ, z)$.

struct Polar{T<:Real, A<:Real}

2-dimensional plane-polar coordinates, denoted by $(s, φ)$.

struct Spherical{T<:Real, A<:Real}

3-dimensional spherical coordinates, denoted by $(r, θ, φ)$.