padecoef

Computes the Pade approximation of time delays.

Syntax

• [numerator, denominator] = padecoef(T, N)
• [numerator, denominator] = padecoef(T)

Input argument

• T - Time delay: a scalar real positive.
• N - Order of approximation: a scalar real positive (default N = 1).

Output argument

• numerator - polynomials of order N: rows vector.
• denominator - polynomials of order N: rows vector.

Description

padecoef(T, N) computes the Nth-order Padé Approximation for the continuous-time delay system represented by the exponential term exp(-T*s) and returns it in the form of a transfer function.

Bibliography

http://en.wikipedia.org/wiki/Pad%C3%A9_approximant and Golub and Van Loan, Matrix Computations, Johns Hopkins University Press (Third edition, page 562).

Example

T = 2; N = 4;
[numerator, denominator] = padecoef(T, N)

See also

tf.

History

Author

Allan CORNET