Detrended Rhythm Oscillator Trough

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
//
// Detrended Rhythm Oscillator (DRO)
// ----------------------------------
// Uses a Detrended Price Oscillator to calculate detrended "zig zag" swings and plots the distance between the last High-High and Low-Low 
//
// Purpose:
// A tool to measure and visualize the current dominant cycle (or rhythm/beat) in the dataset
// Look for common length numbers on the Zig Zag turns to determine the current dominant cycle length, also check for harmonics (2x, 3x)
// You can use the spotted length to optimize the length parameter of technical indicators (use the length or half of the length as input for any technical indicator)
// A technical indicator with the "correct" length setting in regards to the current dominant cycle will provide much better signals
//
// References:
// Zig Zag array functions used from open-source user "LonesomeTheBlue", script Name: "Double Zig Zag with HHLL"
//
// © WhenToTrade

//@version=4
study("Detrended Rhythm Oscillator (DRO) Though", shorttitle="DRO_T", max_lines_count=30, max_bars_back=300, overlay = false)


// { Inputs
// -----------------------------------------------------------------------------
indiversion     = input(              "DRO",   "==== Select Indicator ====", input.string , options=["DRO", "DPO", "BOTH"])
src             = input(              low,                     "  Source", input.source )

fastLength      = input(                  3,                "  Fast Length", type=input.integer, group="DPO")
slowLength      = input(                 20,                "  Slow Length", type=input.integer, group="DPO")

//... ZigZag
zigperiod       = input(                 12,                     "  Period", input.integer, minval=5, group="ZigZag", inline="p")
zigstyle        = input(           "Dashed",                     "  Line -", options = ["Dashed", "Dotted"], group="ZigZag", inline="line")
zigwidth        = input(                  1,                  " Width  -- ", input.integer, options=[1,2,3], group="ZigZag", inline="line") 

showdistanceS   = input(           "On",                         "  Labels", options = ["On", "Off"], group="ZigZag", inline="switch")
showdetrendedS  = input(           "On",                       " Detrended", options = ["On", "Off"], group="ZigZag", inline="switch") 

upcolor         = input(defval = #c0c3c3, title = "  Colors:  Up", group="ZigZag", inline="color")
downcolor       = input(defval = #c0c3c3, title = " Down", group="ZigZag", inline="color")
txtcol          = input(defval = color.yellow, title = " Text", group="ZigZag", inline="color")

//... Switches
showdistance    = (showdistanceS == "On") ? true : false 
showdetrended   = (showdetrendedS == "On") ? true : false  
// } Inputs

// { Variables
// -----------------------------------------------------------------------------
var max_array_size = 10
var ziggyzags = array.new_float(0)
var dir1 = 0
var lastPivot=0
var lastPivotDistance=0
var last_val = 0.0
// } Variables

// { Functions
// -----------------------------------------------------------------------------

add_to_zigzag(pointer, value, bindex)=>
    array.unshift(pointer, bindex)
    array.unshift(pointer, value)
    if array.size(pointer) > max_array_size
        array.pop(pointer)
        array.pop(pointer)
    
update_zigzag(pointer, value, bindex, dir)=>
    if array.size(pointer) == 0
        add_to_zigzag(pointer, value, bindex)
    else
        if (dir == 1 and value > array.get(pointer, 0)) or (dir == -1 and value < array.get(pointer, 0))
            array.set(pointer, 0, value)
            array.set(pointer, 1, bindex)
        0.

// } Functions

// { Calculations
// -----------------------------------------------------------------------------

//... DPO
ppo = 100 * (ema(src, fastLength) - ema(src, slowLength)) / ema(src, slowLength)

//... ZigZag
float highs = highestbars(ppo, zigperiod) == 0 ? ppo : na
float lows = lowestbars(ppo, zigperiod) == 0 ? ppo : na

dir1 := iff(highs and na(lows), 1, iff(lows and na(highs), -1, dir1))

dir1changed = change(dir1)
if highs or lows
    if dir1changed 
        add_to_zigzag(ziggyzags, dir1 == 1 ? highs : lows, bar_index)
    else
        update_zigzag(ziggyzags, dir1 == 1 ? highs : lows, bar_index, dir1)

// } Calculations

// { Plots
// -----------------------------------------------------------------------------

//... Detrended Price Oscillator
plot(indiversion=="DPO" or indiversion=="BOTH" ? ppo : na)

//... Detrended Zig-Zag lines with distance labels
if array.size(ziggyzags) >= 6
    var line zzline1 = na
    var label zzlabel1 = na
    float val = array.get(ziggyzags, 0)
    int point = round(array.get(ziggyzags, 1))
    if change(val) or change(point)
        float val1 = array.get(ziggyzags, 2)
        int point1 = round(array.get(ziggyzags, 3))
        lastPivotDistance:=point-lastPivot
        plabel= tostring(point-lastPivot+lastPivotDistance[lastPivotDistance])
        lastPivot:=point1
        
        if change(val1) == 0 and change(point1) == 0
            if (dir1 != 1)
                label.delete(zzlabel1)
            line.delete(zzline1)
            
        if(indiversion=="DRO" or indiversion=="BOTH")
            zzline1 := line.new(x1 = point, x2 = point1, y1 = showdetrended ? dir1 == 1 ? 100 : -100 : val , y2 = showdetrended ? dir1 == 1 ? -100 : 100 : val1, color = dir1 == 1 ? upcolor : downcolor, width = zigwidth, style = zigstyle == "Dashed" ? line.style_dashed : line.style_dotted)
        
        if ((indiversion=="DRO" or indiversion=="BOTH") and showdistance)
            if (dir1 != 1)
                zzlabel1 := label.new(x = point, y = showdetrended ? (dir1 == 1 ? 75 : -75) : val,  text = plabel, textcolor = txtcol, style = label.style_none, size=size.large) 
                //last_val := point-lastPivot+lastPivotDistance[lastPivotDistance]
                //zzlabel1 := label.new(x = point, y = val,  text = plabel, textcolor = txtcol, style = label.style_none) 
//plot(last_val)

// } Plots