lqstfm: Linear Quaternion Systems Toolbox for Matlab. Matlab is a proprietary software system for calculating with matrices of real and complex numbers, developed and sold by The MathWorks. Quaternions are hypercomplex numbers (that is generalizations of the complex numbers to higher dimensions than two). For an introduction, refer to the Wikipedia article on Quaternions. The Linear Quaternion Systems Toolbox for Matlab® extends Matlab® to allow calculation with linear systems of quaternions. (We will expand on this in due course.)