def abs_thresholds(scale, max_value)
      at = []
      scale.each { |v|
        at.push(v * max_value)
      }
      return at
    end
def abs_thresholds(scale, max_value)
      at = []
      scale.each { |v|
        at.push(v * max_value)
      }
      return at
    end
Produce a thresholds array containing absolute values based on supplied
 percentages applied to a literal max value.