Kama VS HeikinAshi Strategy synapticex

//@version=2
//synapticex.com
kamaPeriod = input(8, minval=1) 
ROCLength=input(4, minval=1) 

kama(length)=>
    volatility = sum(abs(close-close[1]), length)
    change = abs(close-close[length-1])
    er = iff(volatility != 0, change/volatility, 0)
    sc = pow((er*(0.666666-0.064516))+0.064516, 2)
    k = nz(k[1])+(sc*(hl2-nz(k[1])))
    
kamaEntry = security(tickerid,period,kama(kamaPeriod))

plot(kamaEntry, color=gray, title="Kama",transp=0, trackprice=false, style=line)
roc = roc(close, ROCLength)

strategy("Kama VS HeikinAshi", overlay=true, pyramiding=0, calc_on_every_tick=true, calc_on_order_fills=true)

buyEntry =  kamaEntry[0]>kamaEntry[1] and roc[1]<0 and roc >0
sellEntry = kamaEntry[0]<kamaEntry[1] and roc[1]<0 and roc <0

buyExit = kamaEntry<kamaEntry[1] or (roc[1]>0 and roc<0)
sellExit =  kamaEntry>kamaEntry[1] or (roc[1]<0 and roc>0)

if (buyEntry)
    strategy.entry("KAMAL", strategy.long, comment="KAMAL")
else
    strategy.close("KAMAL", when=buyExit)

if (sellEntry)
    strategy.entry("KAMAS", strategy.short, comment="KAMAS")
else
    strategy.close("KAMAS", when=sellExit)