code: def _entropy(p):
      p = p.ravel()
      p1 = p.copy()
      p1 += p == 0
      return -np.dot(np.log2(p1), p)
  
imports: import numpy
  from .None import _texture
  from ..internal import _verify_is_integer_type
label_desc: Use image node_id 1 for calling a global function with example usage: _entropy(p) and returns: unknown