Keeping one value even if same condition is meet again

Question

So I think I need to explain how I'm trying to get this strategy to work before getting in to what the problem is.

So I'm looking at creating a Strategy that if xx candles is clearly under/over a ema(9) make a Triggerline from the first candle that was over/under that ema and do a buy/sell if the ema(1) crclearly osses that line.

So my first problem is this that i'm getting multiple triggers where I only want one trigger

And when I get multiple triggers my triggerLine move which i don't want it to so I need to get ride of the multiple triggers

Here is the code I have so far:

//@version=4
// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © mattehalen



strategy("Mathias & Christer EMA", shorttitle="M&C_EMA",overlay=true, process_orders_on_close = true, default_qty_type =  strategy.percent_of_equity, default_qty_value = 100)
len = input(9, title="Length", type=input.integer)
src = input(close, title="Source", type=input.source)
//show4h = input(true, title="show 4h", type=input.bool)
maxLoss = input(3000)

//ema4h = security(syminfo.ticker, "240", rsi(src, len))
ema4h                   = ema(src, len)
emaCurrent              = ema(src, 1)
difference              = (emaCurrent - ema4h)/ema4h
myATR                   = atr(1)

BuyFirstTrigger         = (difference>myATR) and (emaCurrent>ema4h)
BuyTriggerLineBarssince = barssince(BuyFirstTrigger)
BuyTriggerLine          = close[BuyTriggerLineBarssince] 
BuySignalTest           = crossover(close[1],BuyTriggerLine) and (BuyTriggerLineBarssince > 6)
BuySignalTestBarssince  = barssince(BuySignalTest)
bgcolor(BuySignalTest? color.green : na, transp=20)
bgcolor(BuyFirstTrigger and not BuyFirstTrigger[1]? color.green : na, transp=80)


SellFirstTrigger         = ((difference*-1)>myATR) and (emaCurrent 6)
SellSignalTestBarssince  = barssince(SellSignalTest)
//bgcolor(SellSignalTest and SellSignalTestBarssince[1]>SellTriggerLineBarssince? color.red : na, transp=20)
//bgcolor(SellFirstTrigger and not SellFirstTrigger[1] and SellTriggerLineBarssince[1]>SellTriggerLineBarssince? color.red : na, transp=80)





plot(myATR,title="myATR",display=display.none)
plot(difference,title="difference",display=display.none)
plot(emaCurrent,title="emaCurrent")
plot(ema4h,title="ema4h", color=color.purple, linewidth=5)

//bgcolor(BuyTriggerLineBarssince[1]BuyTriggerLineBarssince
BuySignalBarssince = barssince(BuySignal)
BuySignalOutBarssince = barssince(crossunder(close[1],ema4h[1]))
BuySignalOut   = crossunder(close[1],ema4h[1]) and BuySignalOutBarssince[1]>BuySignalTestBarssince[1]
plot(BuySignalOutBarssince,title="BuySignalOutBarssince",display=display.none)


SellSignal      = SellSignalTest and SellSignalTestBarssince[1]>SellTriggerLineBarssince
SellSignalBarssince = barssince(ema4h[1]>ema4h[0] and ema4h[1]>80)
SellSignalOutBarssince = barssince(crossover(close[1],ema4h[1]))
SellSignalOut   = crossover(close[1],ema4h[1]) and SellSignalOutBarssince[1]>SellSignalTestBarssince[1]


if BuySignal
    strategy.close("short", comment = "Exit short")
    strategy.entry("long", true)
    strategy.exit("Max Loss", "long", loss = maxLoss)

if BuySignalOut
    strategy.close("long", comment = "Exit Long")
if SellSignal
    // Enter trade and issue exit order on max loss.
    strategy.close("long", comment = "Exit Long")
    strategy.entry("short", false)
    strategy.exit("Max Loss", "short", loss = maxLoss)
if SellSignalOut
    // Force trade exit.
    strategy.close("short", comment = "Exit short")


plotchar(BuySignal, "BuySignal", "⬆", location.belowbar, color.lime,size =size.huge )
plotchar(BuySignalOut, "BuySignalOut", "█", location.belowbar, color.lime,size =size.small)
plotchar(SellSignal, "SellSignal", "⬇", location.abovebar ,color.red,size =size.huge)
plotchar(SellSignalOut, "SellSignalOut", "█", location.abovebar, color.red,size =size.small)

alexgrover · Accepted Answer

In order to return a value only the first time a condition is met you can use the following code form:

a = 0
a := condition ? 1 : reset ? 0 : a[1]

and use change(a) ? in order to verify if either condition or reset are met for the first time. Lets take this code as example:

a = 0,b = 0
a := rising(close,14) ? 1 : falling(close,14) ? 0 : a[1]
b := change(a) ? 1 : 0

Here we want b to return 1 the first time close is greater or smaller than any of the previous 14 past close, otherwise 0, both rising and falling can return true consecutively, however b give 1 only for the first time either functions return true.

The plot in green is the one using the previous code, while the one in red always return 1 when both rising or falling are true else 0.

In case you don't want to reset a use:

a = 0
a := condition ? 1 : a[1]

Keeping one value even if same condition is meet again

Answers (1)

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