The Roofing Filter was created by John Ehlers
(Cycle Analytics For Traders pgs
81-82) and this can be interpreted in a few ways. When the indicator crosses over its signal then it is a short term uptrend and when it crosses below its signal then it is a short term downtrend. It is also in a major uptrend or downtrend when it is above 0 and below 0 respectively. Buy when the indicator line is green and sell when the indicator line turns red.
Let me know if there are other indicators you would like to see me publish or if you want something custom done!