Re: Finding multiple roots - RootsInRange.nb (1/1)

*To*: mathgroup at smc.vnet.net*Subject*: [mg39310] Re: Finding multiple roots - RootsInRange.nb (1/1)*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Tue, 11 Feb 2003 04:40:50 -0500 (EST)*Organization*: The University of Western Australia*References*: <asn57g$488$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <asn57g$488$1 at smc.vnet.net>, "Novak Petrovic" <novak at itee.uq.edu.au> wrote: > I'm trying to find roots of the characteristic equation of a > dielectric-loaded waveguide. There are multiple roots of the equation and I > use FindRoot to find them. The sequence of roots is very important in my > further calculations. > > Is there a routine or a clever way to (numerically) find all the roots of an > equation in a predefined values? > > As it is now I have to look for each individual root manually and it gets a > bit tedious as the number of required modes increases. I wrote a function called RootsInRange which does exactly what you want (attached). This originally appeared in The Mathematica Journal which is a good resource for such applications. [contact the author to get the attachment - moderator] Cheers, Paul