# File rbSnack/tkSnackUtil.rb, line 59
  def singleSeg(startPos=0, endPos=nil, minPower=nil, minDuration=nil) 
    minPower=@bkgrnd_power if minPower==nil
    minDuration= @min_duration if minDuration==nil
    endPos = @power.length-1 if endPos==nil
    rtnArry=[]
    x0, peak = nil, nil
    startPos.upto(endPos){ |x|
      y = @power[x]
      if y > minPower
        peak=y if peak==nil
        x0 = x if x0 == nil
        peak=[y,peak].max
      else
        if x0!=nil
          rtnArry<<[x0,x] if x-x0 > minDuration and peak >@min_peak
        end
        x0=nil; 
        peak=nil;
      end      
    }
    rtnArry
  end