我想在3对货币中选择最适合交易的货币： ETHUSDT，BNBUSDT，BTCUSDT。 但是该代码不会编译错误：解决错误
认为期间是问题，因此我尝试了不同时期的代码。没有变化。当我删除结果图时，错误消失了。但是，我猜编译器正在优化并删除问题代码
//START OF STUDY
//@version=3
study("Trio Switcher", overlay=false)
Version=input(1)
// BNBBTC
bnbSwitch = close > nz(open[1]) //or close > close[1]
AltCoin = input("ETH")
alt_bnb_pair = AltCoin + "BNB"
alt_btc_pair = AltCoin + "BTC"
alt_bnb_ticker=heikinashi(tickerid(syminfo.prefix,alt_bnb_pair))
alt_btc_ticker=heikinashi(tickerid(syminfo.prefix,alt_btc_pair))
//BNB base
alt_bnb_open = security(alt_bnb_ticker, period, open)
alt_bnb_close = security(alt_bnb_ticker, period, close)
//BTC base
alt_btc_open = security(alt_btc_ticker, period, open)
alt_btc_close = security(alt_btc_ticker, period, close)
altSwitch = bnbSwitch ? alt_bnb_close > nz(alt_bnb_open[1]) : alt_btc_close > nz(alt_btc_open[1])
ALTPAIR = 2
BNBPAIR = 1
BTCPAIR = 0
activePair = altSwitch ? ALTPAIR : bnbSwitch ? BNBPAIR : BTCPAIR
alertcondition(activePair==ALTPAIR, "ALT")
alertcondition(activePair==BNBPAIR, "BNB")
alertcondition(activePair==BTCPAIR, "BTC")
plot(activePair)
//END OF STUDY
将此指标添加到周期为1W的BNBBTC图表中时，它应该只绘制0、1或2