This concept from Brett Steenbarger as following:
http://traderfeed.blogspot.com/2009/03/ ... asure.html
Frist, calculate the difference btw close of current bar and close of the previous one. Do that for 20 previous bars
Then, calculate the volatility of the current bar (High minus Low then divided by the Low). The same for 20 previous bars
Finally, running 20-bar correlation between the series of step 1 and step 2. That correlation is power measure. Post this line on the chart as overlay. This will express both price change and its volatility on a single indicator. It will be neat and convenient
Thanks