[ANN] Quaternions.jl v0.7.0

[hyrodium]

@sethaxen and I have been working on maintaining the Quaternion.jl this year.

Today, version v0.7.0 has been released with some breaking changes, and this will likely be the last release before v1.0.0.

The changes we worked on include:

• Octonion has been removed.
  • Octonions.jl now provides this type.
• DualQuaternion has been removed.
  • Quaternion{ForwardDiff.Dual} can take its place.
• The field norm::Bool has been removed from Quaternion struct.
  • This field was used as a flag to indicate whether the quaternions were normalized or not, but it was inefficient.
  • See Makie.jl/quaternions.jl at f2970dcd77bc16f311f8bb3226ef7d716395b369 · MakieOrg/Makie.jl · GitHub.
• Complex-Quaternion compatibility has been removed.
  • This is because we cannot choose one natural mapping \mathbb{C} \to \mathbb{H}.
  • The previous implementation for the compatibility was incomplete, and we choose to remove them.
• Add more tests
  • Coverage 43% → 99%
• Add documentation page with Documenter.jl
  • Home · Quaternions.jl
• Rotation-related functions have been removed.
  • Quaternions.jl used to provide a function that converts a unit quaternion to DCM. This function was inefficient because the return type was Matrix{Float64} but not StaticMatrix{3,3,Float64}.
  • Rotations.jl provides a similar function with StaticMatrix.
• The Base’s analytic functions have been extended to quaternion.
  • See Extend all analytic functions in base for quaternions by sethaxen · Pull Request #56 · JuliaGeometry/Quaternions.jl · GitHub for more information.

Note that some other packages define their own Quaternion struct.

• Makie.jl
• Quaternionic.jl
• ReferenceFrameRotations.jl

The Quaternions.jl package does not have dependencies except for standard packages, and is maintained under JuliaGeometry organization. I hope every other package which uses quaternions has a dependency on our Quaternions.jl package.

Here’s the package logo designed with Luxor.jl.

[kellertuer]

It took me quite a while to find this, but

normalize(q::Quaternion) was removed and (to be consistent with LinearAlgebra) there is not sign(q).

[_stla]

Looks good. Do you intend to implement the usual mathematical functions such as the exponential and the logarithm? They are useful.

[stevengj]

@_stla

Do you intend to implement the usual mathematical functions such as the exponential and the logarithm? They are useful.

They are already implemented here and here.

[sethaxen]

@_stla

Looks good. Do you intend to implement the usual mathematical functions such as the exponential and the logarithm? They are useful.

As @stevengj pointed out, these are implemented already, but we also extend all complex analytic functions defined in Base to the quaternions and offer a function extend_analytic that a user can use to extend any other complex analytic function.