function [left, right] = ggdfwhm(mu, alpha, beta)
  % Half the Maximum:
  hm = ggdpdf(mu, mu, alpha, beta) / 2;

  f = @(x)(ggdpdf(x, mu, alpha, beta) - hm);

  % Find roots left and right of center peak:
  left  = fzero(f, [mu - 3 * alpha, mu]);
  right = fzero(f, [mu, mu + 3 * alpha]);
end

function p = ggdpdf(x, mu, alpha, beta)
  %
  % PDF of Generalized Gaussian Distribution
  %   https://en.wikipedia.org/wiki/Generalized_normal_distribution
  %
  % Equivalent to normpdf if beta == 2; then sigma = alpha^2 / 2.
  %

  p = beta ./ (2 * alpha * gamma(1/beta)) .* exp(-(abs(x-mu)/alpha).^beta);
end