code: def hall_sheather(n, q, alpha=0.05):
      z = norm.ppf(q)
      num = 1.5 * norm.pdf(z) ** 2.0
      den = 2.0 * z**2.0 + 1.0
      h = (
          n ** (-1.0 / 3)
          * norm.ppf(1.0 - alpha / 2.0) ** (2.0 / 3)
          * (num / den) ** (1.0 / 3)
      )
      return h
  
imports: import numpy
  import warnings
  import scipy.stats
  from numpy.linalg import pinv
  from scipy.stats import norm
  from statsmodels.tools.decorators import cache_readonly
  from statsmodels.regression.linear_model import RegressionModel, RegressionResults, RegressionResultsWrapper
  from statsmodels.tools.sm_exceptions import ConvergenceWarning, IterationLimitWarning
label_desc: Use image node_id 2 for calling a global function with example usage: hall_sheather(n, q, alpha) and returns: h