code: def errfunc(p, x, y):
      return np.power(y - fitfunc(p, x), 2)
  
file_path: scattertext/scattertext/smoothing/power_law.py
imports: import numpy
  from scipy.optimize import leastsq
label_desc: Use image node_id 2 for calling a global function with example usage: errfunc(p, x, y) and returns: np