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Homework Help: Finding the zeros of a complex function in PyLab

  1. Jun 22, 2014 #1
    I have this characteristic equation for the wave number eigenvalues [itex] k_n [/itex] of a homogeneous infinte cylinder of radius R:

    [itex] D_{m} = (k_n R) = 0, [/itex]


    [itex] D_m (z) = n_r J'_m(n_r z)H_m(z) - J_m(n_r z)H'_m(z) [/itex]

    and [itex] n_r [/itex] is the refractive index of the cylinder, the bessel and hankel functions are both of the first kind, and z is a complex argument. I'm not sure how I can solve for the zeros of this. I've been using PyLab, but haven't found any clues as to what I should do.

    The article I'm working from is: http://arxiv.org/abs/1302.0245
    These are equations (18) and (19) from the article

    I'm new to this, so I may be trying something ridiculous.
  2. jcsd
  3. Jun 23, 2014 #2
    An even simpler statement of my problem: How can I find the zeros of a complex function in PyLab? Most sources I've found haven't helped.
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