EMA Strategy

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © capissimo

//@version=4 
study("EMA Strategy", '', true, precision=4)

// EMA Strategy aka Pip Collector Mod

// This script was inspired by LazyBear's popular script
// called Pip collector. It features custom signal generation
// and information section displaying elapsed bar time useful 
// for timing trades.

//-------------------- Inputs

ds           = input(close, 'Dataset')
lengthCenter = input(50,    'Center EMA Length |1..n|', minval=1, maxval=2160)
length       = input(20,    'Upper/Lower Distance from Center (PIPs) |-n..n|')
fltr         = input(true,  'Filter Out Signals By Volatility?')
holding_p    = input(5,     'Holding Period |1..n|',    minval=1, maxval=240)
show_info    = input(true,  'Display information?')

//-------------------- System Variables

var BUY = -1
var SELL = 1
var HOLD = 0

//-------------------- Dynamic Arrays

var int   signal     = HOLD
var int   hp_counter = 0
var label lbl        = na

//-------------------- Custom Functions

cGreen(g) =>  g>9?#006400:g>8?#1A741A:g>7?#338333:g>6?#4D934D:g>5?#66A266
             :g>4?#80B280:g>3?#99C199:g>2?#B3D1B3:g>1?#CCE0CC:#E6F0E6
cRed(g)   =>  g>9?#E00000:g>8?#E31A1A:g>7?#E63333:g>6?#E94D4D:g>5?#EC6666
             :g>4?#F08080:g>3?#F39999:g>2?#F6B3B3:g>1?#F9CCCC:#FCE6E6
             
//-------------------- Logic

pip     = syminfo.mintick 

ma    = ema(ds, lengthCenter)
upper = ma + length * pip
lower = ma - length * pip

filter  = fltr ? atr(1) > atr(10) : true   //-- filter out by volatility
signal := close > lower and filter ? BUY : close < upper and filter ? SELL : nz(signal[1])

changed = change(signal)

hp_counter := changed ? 0 : hp_counter + 1

startLongTrade  = changed and signal==BUY    
startShortTrade = changed and signal==SELL   
endLongTrade    = (signal==BUY  and hp_counter==holding_p and not changed) //-- TOADD: stop by trade duration
endShortTrade   = (signal==SELL and hp_counter==holding_p and not changed) 

//-------------------- Rendering

plot(ma,    'Center EMA', color.blue,  2)
plot(lower, 'Lower',      color.red,   2)
plot(upper, 'Upper',      color.green, 2)

plotshape(startLongTrade  ? low   : na, 'Buy',  shape.labelup,   location.absolute, cGreen(7), size=size.small)
plotshape(startShortTrade ? high  : na, 'Sell', shape.labeldown, location.absolute, cRed(7),   size=size.small)
plot(endLongTrade         ? ohlc4 : na, 'StopBuy',  cGreen(6), 2, plot.style_cross)
plot(endShortTrade        ? ohlc4 : na, 'StopSell', cRed(6),   2, plot.style_cross)

//-------------------- Alerting

alertcondition(startLongTrade,  'Buy',  'Go long!')
alertcondition(startShortTrade, 'Sell', 'Go short!') 
alertcondition(startLongTrade or startShortTrade, 'General Alert', 'Deal Time!')

//------------------- Information

// countdown in %
tbase = (time - time[1]) / 1000
tcurr = (timenow - time_close[1]) / 1000

info = 'Bar Time: ' + tostring(tcurr / tbase, '#.#%')

if show_info and barstate.islast  
    lbl := label.new(bar_index, ohlc4, info, xloc.bar_index, yloc.price, 
                     color.new(color.blue, 100), label.style_label_left, color.black, size.small, text.align_left)
    label.delete(lbl[1])