240 Chapter 6. Function Reference
The primary use of this routine is the fitting of Dscale weightsfor mu synthesis
iterations.
Chebyshev polynomials areused as basis functions for both the numerator and
denominator polynomials.
WARNING:This ro utine uses iterativep olynomial calculations which are not well
conditioned for high order (>6) fits.
Reference
For further information see: “Curve Fitter for Pole-Zero Analysis,” J.L. Adcock,
Hewlett-PackardJournal, p. 33, January 1987.
Example
# Set up a plant to generated data for the fitting
# problem.
plant = makepoly([0.1,-0.1,1],"s")*makepoly([1,1],"s")...
/(makepoly([1,0.1,.1],"s")*(makepoly([0.2,1],"s")))
# Note that plant has right half plane zeros
rifd(plant)
Poles:
real imaginary frequency damping
(rad/sec) ratio
-5.0000e-02 3.1225e-01 3.1623e-01 0.1581
-5.0000e-02 -3.1225e-01 3.1623e-01 0.1581
-5.0000e+00 0.0000e+00 5.0000e+00 1.0000
Zeros: