# [blackcat] L2 Ehlers Phase Accumulator Cycle Period Measurer

Level: 2

Background

John F. Ehlers introuced Phase Accumulation technique of cycle period measurement in his "Rocket Science for Traders" chapter 7. It is perhaps the easiest to comprehend. In this technique, John Ehlers measures the phase at each sample by taking the arctangent of the ratio of the Quadrature component to the In-phase component. A delta phase is generated by taking the difference of the phase between successive samples. At each sample Dr . Ehlers then looks backward, adding up the delta phases. When the sum of the delta phases reaches 360 degrees (2*pi in tradingview), we must have passed through one full cycle, on average. The process is repeated for each new sample.

Function
blackcat L2 Ehlers Phase Accumulator Cycle Period Measurer is used to measure Dominant Cycle (DC). This is one of John Ehlers three major methods to measure DC. The Phase Accumulation method of cycle measurement always uses one full cycle’s worth of historical data. This is both an advantage and disadvantage. The advantage is the lag in obtaining the answer scales directly with the cycle period. That is, the measurement of a short cycle period has less lag than the measurement of a longer cycle period. However, the number of samples used in making the measurement means the averaging period is variable with cycle period. Longer averaging reduces the noise level compared to the signal. Therefore, shorter cycle periods necessarily have a higher output Signal-to-Noise Ratio ( SNR ).

Key Signal

Smooth --> 4 bar WMA w/ 1 bar lag
Detrender --> The amplitude response of a minimum-length HT can be improved by adjusting the filter coefficients by
trial and error. HT does not allow DC component at zero frequency for transformation. So, Detrender is used to remove DC component/ trend component.
I1 --> In-phase signal
Period --> Dominant Cycle in bars

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 2nd script for Blackcat1402 John F. Ehlers Week publication.

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.

Donate TRC20 USDT to below address, 5USDT per monthly sub, 50USDT per yearly sub: TNz84MjJTWUUUyQFpPNjaAU7J2SwhJJ7j9
Note: USDT_TRC20 deposits sent from decentralized exchanges are not yet supported.
Mã nguồn mở

Với tinh thần TradingView, tác giả của tập lệnh này đã xuất bản nó dưới dạng mã nguồn mở, vì vậy các nhà giao dịch có thể hiểu và xác minh nó. Chúc mừng tác giả! Bạn có thể sử dụng mã này miễn phí, nhưng việc sử dụng lại mã này trong một ấn phẩm chịu sự điều chỉnh của Nội quy nội bộ. Bạn có thể yêu thích nó để sử dụng nó trên biểu đồ.

Thông báo miễn trừ trách nhiệm

Thông tin và ấn phẩm không có nghĩa là và không cấu thành, tài chính, đầu tư, kinh doanh, hoặc các loại lời khuyên hoặc khuyến nghị khác được cung cấp hoặc xác nhận bởi TradingView. Đọc thêm trong Điều khoản sử dụng.

Bạn muốn sử dụng tập lệnh này trên biểu đồ?