code: def cost(z):
      """Cost function for multi-fidelity. The cost is linear in both the resolution and
      the amount of data used. The 1e-5 is to ensure that the cost function is never 0.
      """
      resolution = _get_resoltion_from_z0(z[0])
      return 1e-5 + (resolution / float(RESOLUTION_MAX)) * (
          z[1] / float(NUM_DATA_MAX)
      )
  
imports: import numpy
  from scipy.stats import norm
  from scipy import integrate
label_desc: Use image node_id 3 for calling a global function with example usage: cost(z) and returns: unknown