docs: def valueAt( self, percent ):
          """
          Returns the value at the inputed percent.
          
          :param     percent | <float>
          
          :return     <variant>
          """
          minim = self.minimum()
          maxim = self.maximum()
          rtype = self.rulerType()
          
          # simple minimum
          if ( percent <= 0 ):
              return minim
          
          # simple maximum
          elif ( 1 <= percent ):
              return maxim
          
          # calculate a numeric percentage value
          elif ( rtype == XChartRuler.Type.Number ):
              return (maxim - minim) * percent
          
          # calculate a time percentage value
          elif ( rtype in (XChartRuler.Type.Datetime, XChartRuler.Type.Time) ):
              maxsecs = minim.secsTo(maxim)
              
              diff = maxssecs * percent
              return minim.addSecs(diff)
              
          # calculate a date percentage value
          elif ( rtype == XChartRuler.Type.Date ):
              maxdays = minim.daysTo(maxim)
              
              diff = maxdays * percent
              return minim.addDays(diff)
              
          # otherwise, compare against the notches
          else:
              perc    = 0.0
              notches = self.notches()
              count   = len(notches)
              count  += self.padStart() + self.padEnd()
              count   = max(1, count - 1)
              
              perc    = float(self.padStart()) / count
              last    = None
              
              for i, notch in enumerate(notches):
                  perc += float(i) / count
                  if ( perc <= percent ):
                      break
                  
                  last = notch
              
              return last