[blackcat] L2 Ehlers Modified RSI Indicator

1 Nov 2020

Level: 2

Background

John F. Ehlers introuced Modified RSI Indicator in his "Cycle Analytics for Traders" chapter 7 on 2013.


Function

The RSI is the percentage of the sum of the delta closes up to the sum of all the delta closes over the observation period. The only variable here is the observation period. To have maximum effectiveness the observation period should be half of the measured period. If the observation period is half the dominant cycle, then for a pure sine wave, the closes up is exactly equal to the total closes during part of the cycle from the valley to the peak. In this case, the RSI would have a value of 100. During another part of the cycle—the next half cycle—there would be no closes up. During this half cycle, the RSI would have a value of zero. So, in principle, half the measured cycle is the correct choice for the RSI observation period.

A modified RSI that is a standard RSI preceded by a SuperSmoother filter. The modified RSI is far more responsive and has less lag because the low frequency components have have been removed by the high-pass part of the SuperSmoother filter. The RSI is functionally the same as a single-pole high-pass filter because the CU term in the numerator is just a summation of one-bar differences.

Key Signal

MyRSI --> Modified RSI Indicator fast line
Trigger --> Modified RSI Indicator slow line

Pros and Cons

100% John F. Ehlers definition translation of original work, even variable names are the same. This help readers who would like to use pine to read his book. If you had read his works, then you will be quite familiar with my code style.

Remarks

The 45th script for Blackcat1402 John F. Ehlers Week publication.

Readme

In real life, I am a prolific inventor. I have successfully applied for more than 60 international and regional patents in the past 12 years. But in the past two years or so, I have tried to transfer my creativity to the development of trading strategies. Tradingview is the ideal platform for me. I am selecting and contributing some of the hundreds of scripts to publish in Tradingview community. Welcome everyone to interact with me to discuss these interesting pine scripts.

The scripts posted are categorized into 5 levels according to my efforts or manhours put into these works.

Level 1 : interesting script snippets or distinctive improvement from classic indicators or strategy. Level 1 scripts can usually appear in more complex indicators as a function module or element.

Level 2 : composite indicator/strategy. By selecting or combining several independent or dependent functions or sub indicators in proper way, the composite script exhibits a resonance phenomenon which can filter out noise or fake trading signal to enhance trading confidence level.

Level 3 : comprehensive indicator/strategy. They are simple trading systems based on my strategies. They are commonly containing several or all of entry signal, close signal, stop loss, take profit, re-entry, risk management, and position sizing techniques. Even some interesting fundamental and mass psychological aspects are incorporated.

Level 4 : script snippets or functions that do not disclose source code. Interesting element that can reveal market laws and work as raw material for indicators and strategies. If you find Level 1~2 scripts are helpful, Level 4 is a private version that took me far more efforts to develop.

Level 5 : indicator/strategy that do not disclose source code. private version of Level 3 script with my accumulated script processing skills or a large number of custom functions. I had a private function library built in past two years. Level 5 scripts use many of them to achieve private trading strategy.