class_docstr: A mixin class to map scalar data to RGBA.
  
  The ScalarMappable applies data normalization before returning RGBA colors
  from the given colormap.
docstr: Autoscale the scalar limits on the norm instance using the
  current array, changing only limits that are None
docstr_tok: ["Autoscale","the","scalar","limits","on","the","norm","instance","using","the","current","array",",","changing","only","limits","that","are","None"]
code: def autoscale_None(self):
      """
      Autoscale the scalar limits on the norm instance using the
      current array, changing only limits that are None
      """
      if self._A is None:
          raise TypeError("You must first set_array for mappable")
      # If the norm's limits are updated self.changed() will be called
      # through the callbacks attached to the norm
      self.norm.autoscale_None(self._A)
  
imports: from collections.abc import Mapping
  import functools
  import numpy
  from numpy import ma
  import matplotlib
  from matplotlib import _api, colors, cbook, scale
  from matplotlib._cm import datad
  from matplotlib._cm_listed import cmaps
label_desc: Use image node_id 15 for calling the ScalarMappable obj's underlying member method code with example usage: obj.autoscale_None() without return types