code: def makeLabel(self, value):
          
          value, prefix = format_units(value, self.step,
                                       system=self.unitSystem)
          span, spanPrefix = format_units(self.span, self.step,
                                          system=self.unitSystem)
          if prefix:
              prefix += " "
          if value < 0.1:
              return "%g %s" % (float(value), prefix)
          elif value < 1.0:
              return "%.2f %s" % (float(value), prefix)
          if span > 10 or spanPrefix != prefix:
              if type(value) is float:
                  return "%.1f %s" % (value, prefix)
              else:
                  return "%d %s" % (int(value), prefix)
          elif span > 3:
              return "%.1f %s" % (float(value), prefix)
          elif span > 0.1:
              return "%.2f %s" % (float(value), prefix)
          else:
              return "%g %s" % (float(value), prefix)
docs: Create a label for the specified value.
  
          Create a label string containing the value and its units (if any),
          based on the values of self.step, self.span, and self.unitSystem.