Cycles can be spotted by using a wide range of methods, most of them will involve bandpass filtering, here i will show a method using recursion with the change() function.
The Indicator
As i explained in other indicators using recursion i posted rescaling the input is important, i will use the rsi of an exponential moving average as input. alpha control the amount of output the indicator will use as input, values closer to 0.5 will use more input resulting in more periodic results.
Lowering alpha when length is higher can help get more periodic results.
Conclusion
I have showed a new cycle indicator using recursion. Recursion with oscillators can highlights cycles in price thus being easier to predict.