Matrice compagnon

• companion — matrice compagnon
• ereduc — computes matrix column echelon form by qz transformations
• fstair — computes pencil column echelon form by qz transformations
• glever — inverse d'un faisceau de matrices
• kroneck — Kronecker form of matrix pencil
• lyap — Equation de Lyapunov
• pencan — canonical form of matrix pencil
• penlaur — Laurent coefficients of matrix pencil
• quaskro — quasi-Kronecker form
• randpencil — random pencil
• rowshuff — shuffle algorithm