code: def kaiser_beta(a):
      """Compute the Kaiser parameter `beta`, given the attenuation `a`.
      Parameters
      ----------
      a : float
          The desired attenuation in the stopband and maximum ripple in
          the passband, in dB.  This should be a *positive* number.
      Returns
      -------
      beta : float
          The `beta` parameter to be used in the formula for a Kaiser window.
      References
      ----------
      Oppenheim, Schafer, "Discrete-Time Signal Processing", p.475-476.
      """
      if a > 50:
          beta = 0.1102 * (a - 8.7)
      elif a > 21:
          beta = 0.5842 * (a - 21) ** 0.4 + 0.07886 * (a - 21)
      else:
          beta = 0.0
      return beta
  
file_path: cusignal/python/cusignal/filter_design/fir_filter_design.py
imports: from math import ceil, log
  import cupy
  import numpy
  from scipy import signal
  from ..windows.windows import get_window
label_desc: Use image node_id 2 for calling a global function with example usage: kaiser_beta(a) and returns: beta