code: def _coverage_max(dmin, dmax, span):
      range_ = dmax - dmin
      if span <= range_:
          return 1.0
      else:
          half = (span - range_) / 2.0
          return 1 - half**2 / (0.1 * range_) ** 2
  
imports: import math
  import numpy
  from .visual import CompoundVisual, updating_property
  from .line import LineVisual
  from .text import TextVisual
label_desc: Use image node_id 3 for calling a global function with example usage: _coverage_max(dmin, dmax, span) and returns: int, unknown