rational
Description
Use the rational
object and an interpolative algorithm to
create a rational fit to frequency-dependent data.
The fit is given by the equation:
Creation
Syntax
Description
[
also returns the error of the fit. Use any of input argument combinations
from the previous syntaxes.fit
,error
] = rational(___)
specifies options to control aspects of fit or sets properties. You can set the NumPoles, Poles, Residues, and DirectTerm properties (since R2023a) using name-value
arguments. For example, fit
= rational(___,Name=Value)fit = rational(s,MaxPoles=1002)
sets the maximum number of poles for the fit. Specify name-value arguments
after any of the input arguments from the previous syntaxes.
Input Arguments
Properties
Object Functions
timeresp | Time response for rational objects |
stepresp | Step-signal response for rational object and rationalfit function
object |
freqresp | Frequency response of rational object and rationalfit function
object |
pwlresp | Calculate time response of piecewise linear input signal |
impulse | Impulse response for rational function object |
ispassive | Return true if rationalfit output is passive at all
frequencies |
makepassive | Enforce passivity of rationalfit output or a rational
object |
passivity | Plot passivity of N-by-N
rationalfit function output |
generateSPICE | Generate SPICE file from rationalfit of
S-parameters |
abcd | Construct state-space matrices from rational
object |
zpk | Compute zeros, poles, and gain of rational object |
Examples
References
[1] Nakatsukasa, Yuji, Olivier Sète, and Lloyd N. Trefethen. “The AAA Algorithm for Rational Approximation.” SIAM Journal on Scientific Computing 40, no. 3 (January 2018): A1494–1522. https://doi.org/10.1137/16M1106122.