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Article #249Re: Graph-TI - Fourier Series
From: Mark Janeba
Date: Thu, 27 Oct 1994 21:44
Date: Thu, 27 Oct 1994 21:44
25 lines
1647 bytes
1647 bytes
On 27 Oct 1994, Fleet Rapid Response wrote:
>
> Does anybody know of a program to claculate fourier series?
Why program? Try this: For a function on [-1,1], to find a Fourier sine
series (i.e. f is odd):
Put f(x) in y1. Then the Nth Fourier coefficient is
fnInt(y1*sin(N*\Pi\*x),x,-1,1) (Use "N" and not "n" or the '85 balks).
So compute a bunch of coefficients (say the first five) at once:
seq(fnInt(y1*sin(N*\Pi\*x),x,-1,1),N,1,5,1) -> C
To check your work, graph y1 against
y2=sum seq (C(N)*sin(N*\Pi\*x),N,1,5,1).
If you want cosine series, or some other interval, modify accordingly.
Mark Janeba (503)370-6123
Dept. of Mathematics e-mail: mjaneba@willamette.edu
Willamette University "Speaking for myself, not the university"
Salem, Oregon 97301-3922 USA
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 104512,7eb174ed154d7c4b X-Google-Attributes: gid104512,public X-Google-ArrivalTime: 1994-10-27 14:44:56 PST Path: arc1-ca.pugleaf.net!nntp.gmd.de!Germany.EU.net!EU.net!howland.reston.ans.net!swrinde!news.dell.com!paladin.american.edu!auvm!willamette.edu!mjaneba Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU Newsgroups: bit.listserv.graph-ti Date: Thu, 27 Oct 1994 14:44:56 -0700 (PDT) From: Mark Janeba <mjaneba@willamette.edu> Subject: Re: Graph-TI - Fourier Series cc: GRAPH-TI@ds0.internic.net In-Reply-To: <38o202$dsp@bs33n.staffs.ac.uk> Message-ID: <Pine.3.89.9410271409.A28674-0100000@jupiter> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-graph-ti@dsmail.internic.net Precedence: bulk Reply-To: Mark Janeba <mjaneba@willamette.edu> Lines: 25