Article View: comp.dsp
Article #354Taylor vs. Chebyshev polynomials
From: Myron A. Calhoun
Date: Tue, 03 Oct 1989 01:03
Date: Tue, 03 Oct 1989 01:03
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In article <1989Sep28.161516.10353@rpi.edu> wrf@mab.ecse.rpi.edu (Wm Randolph Franklin) writes:
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>You can work out how many Taylor terms it would take to get that
>accuracy. Editorial: Taylor series are for wimps.
I'm under the impression that in any given range which doesn't have
singularity points, Chebyshev polynomials (of the first kind) can be
used to "telescope" Taylor series of degree N down to degree N-1
while retaining the same maximum error (but this error may pop up in
places where it wasn't present in the original--kinda like squeezing
a balloon). The difference between N and N-1 is only ONE term
(although for some common trig functions which have only even- or odd-
powered terms, it may LOOK like two?); which seems rather "wimpy" to me.
I can see that if I'm going to calculate a particular series a jillion
times, one less calculation would be nice, but I don't see that as
being particularly significant otherwise. Do other Chebyshev
polynomials provide even better telescoping?
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--Myron.
--
Myron A. Calhoun, PhD EE, W0PBV, (913) 532-6350 (work), 539-4448 (home).
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Path: arc1-ca.pugleaf.net!utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!deimos.cis.ksu.edu!harris.cis.ksu.edu!mac From: mac@harris.cis.ksu.edu (Myron A. Calhoun) Newsgroups: comp.dsp,rec.audio Subject: Taylor vs. Chebyshev polynomials Keywords: Taylor vs. Chebyshev polynomials Message-ID: <3811@deimos.cis.ksu.edu> Date: 3 Oct 89 01:03:47 GMT References: <2421@radio.oakhill.UUCP> <1989Sep28.161516.10353@rpi.edu> Sender: news@deimos.cis.ksu.edu Reply-To: mac@harris.cis.ksu.edu (Myron A. Calhoun) Followup-To: comp.dsp Organization: Kansas State University, Dept of Computing & Information Sciences Lines: 29