code: def _initial_nodes(n):
      """Initial guesses for the Hermite roots
  
      Computes an initial approximation to the non-negative
      roots :math:`x_k` of the Hermite polynomial :math:`H_n`
      of order :math:`n`. The Tricomi and Gatteschi initial
      guesses are used in the region where they are accurate.
  
      Parameters
      ----------
      n : int
          Quadrature order
  
      Returns
      -------
      xk : ndarray
          Approximate roots
  
      See Also
      --------
      roots_hermite_asy
      """
      # Turnover point
      # linear polynomial fit to error of 10, 25, 40, ..., 1000 point rules
      fit = 0.49082003 * n - 4.37859653
      turnover = around(fit).astype(int)
      # Compute all approximations
      ia = arange(1, int(floor(n * 0.5) + 1))
      ib = ia[::-1]
      xasq = _initial_nodes_a(n, ia[: turnover + 1])
      xbsq = _initial_nodes_b(n, ib[turnover + 1 :])
      # Combine
      iv = sqrt(hstack([xasq, xbsq]))
      # Central node is always zero
      if n % 2 == 1:
          iv = hstack([0.0, iv])
      return iv
  
imports: import numpy
  from numpy import exp, inf, pi, sqrt, floor, sin, cos, around, hstack, arccos, arange
  from scipy import linalg
  from scipy.special import airy
  from .None import _specfun
  from .None import _ufuncs
label_desc: Use image node_id 14 for calling a global function with example usage: _initial_nodes(n) and returns: iv