交易视图 ta.crossover

Question

I'm looking to use the function plotshape() to display a flag when there is a crossover in 3 instances such as:

1. EMA8 crosses over the EMA113 and WMA200
2. EMA24 crosses over the EMA113 and WMA200
3. WMA50 crosses over the EMA113 and WMA200

When I use the and function the flag displays only when the crossover happens on a single bar When I use the or function the flag displays twice

I'm looking to have 1 flag plotted after then cross of both lines happens

Example: EMA8 crosses over EMA113 (no flag) crossover WMA200 flag where the condition of the previous cross of EMA113 is true

Hopefully this makes sense and thank you!

 EMA8_= ta.ema(close,8)
    EMA24_= ta.ema(close,24)
    WMA50_= ta.wma(close,50)
    EMA113_= ta.ema(close,113)
    WMA200_= ta.wma(close,200)
    
    ema8=plot(ta.ema(close,8),color=color.white)
    ema24=plot(ta.ema(close,24),color=color.yellow)
    wma50=plot(ta.wma(close,50),color=color.red)
    ema113=plot(ta.ema(close,113),color=color.aqua)
    wma200=plot(ta.wma(close,200),color=color.blue)
    
    plotshape(series = (ta.crossover(EMA8_, EMA113_)) and (ta.crossover(EMA8_, WMA200_)) , style=shape.flag, location=location.top, color=#9FE2BF, size=size.normal)
    plotshape(series = (ta.crossover(EMA24_, EMA113_)) and (ta.crossover(EMA24_, WMA200_)) , style=shape.flag, location=location.top, color=#FFC000, size=size.normal)
    plotshape(series = (ta.crossover(WMA50_, EMA113_)) and (ta.crossover(WMA50_, WMA200_)) , style=shape.flag, location=location.top, color=#FF5F15, size=size.normal)

AND

or

Answer 1

There are multiple ways of doing this. In all cases, you should think about having a variable that becomes true only for one bar where your condition becomes true.

You should implement your logic based on that, or you can use functions that return true when a specific event happens. Using ta.crossover() is indeed correct here.

Let's look at your condition 1.

EMA8 crosses over the EMA113 and WMA200

First, find if EMA8 crosses over EMA113 or WMA200. When that is true , check if EMA8 is greater than both of them. You need to use crossover function here to only trigger your flag once a crossover happens. Then by comparing the actual values, you also check if the other crossover happened sometime in the past. Because if EMA8 crossed over EMA113 or WMA200 in the past, its value would be greater than that.

Here is the code for your condition 1. You can adapt it for your other conditions.

//@version=5
indicator("My Script")
EMA8_= ta.ema(close,8)
EMA113_= ta.ema(close,113)
WMA200_= ta.wma(close,200)
bool isCond1 = (ta.crossover(EMA8_, EMA113_) or ta.crossover(EMA8_, WMA200_)) and (EMA8_ > EMA113_) and (EMA8_ > WMA200_)

plot(ta.ema(close,8),color=color.white)
plot(ta.ema(close,113),color=color.aqua)
plot(ta.wma(close,200),color=color.blue)
plotshape(series = isCond1 , style=shape.flag, location=location.top, color=#9FE2BF, size=size.normal)