Digital Fractional Order Differentiator/inte​grator - IIR type

General IIR digital differentiator/integrator.

A new general IIR digital fractional order differentiator/integrator based on continued fraction expansion of weighted operator which is mixed scheme of the trapezoidal (Tustin) rule and the backward difference (Euler) rule.

For more details see books:
[1] Ivo Petras, Fractional-Order Nonlinear Systems: Modeling, Analysis and Simulation, Springer, Series: Nonlinear Physical Science, 2011, ISBN 978-3-642-18100-9. http://www.springer.com/engineering/control/book/978-3-642-18100-9
[2] Riccardo Caponetto, Giovanni Dongola, Luigi Fortuna and Ivo Petras, Fractional Order Systems: Modeling and Control Applications, World Scientific, Singapore, 2010, ISBN 978-9-814-30419-1. http://www.worldscibooks.com/chaos/7709.html
[3] Ivo Petras, Fractional Derivatives, Fractional Integrals, and Fractional Differential Equations in Matlab, chapter 10, in: Engineering Education and Research Using MATLAB, Ali H. Assi (Ed.), InTech, ISBN 978-953-307-656-0. http://www.intechopen.com/articles/show/title/fractional-derivatives-fractional-integrals-and-fractional-differential-equations-in-matlab