This class library enable Quaternion arithmetic as easily as Complex.Quaternion are to 3D space rotations what Complex numbers are to 2D plane rotations.Quaternion can be created from real and unreal part like:1 + 2 i - 1 j + 3 k.They can do arithmetic (non commutative ring).Usual functions like exp cos ... can be defined (by usual power series expansion).You can load in Squeak with this incantation:Installer ssproject: 'MetacelloRepository';package: 'ConfigurationOfQuaternion';install.((Smalltalk at: #ConfigurationOfQuaternion) project version: #'stable') perform: #load.or in Pharo with:Gofer newsqueaksource: 'MetacelloRepository';package: 'ConfigurationOfQuaternion';load.((Smalltalk at: #ConfigurationOfQuaternion) project version: #'stable') perform: #load.