Amibroker AFL code Buy Sell status is not fetching with if condition - algorithmic-trading

Question

I have AFL which is working fine for crude oil. out of 10 trades, 8 trades are targets hitting. I have code for place orders auto trades. the auto trade code is working fine with other AFL codes but the problem is in below algorithm the BUY and SELL Boolean value is not giving to IF condition. But IIF(Buy .... conditions are working fine.
My main question is why BUY Sell True or false is not working in the last status in AFL. Kindly help me to resolve this.
_SECTION_BEGIN("T+4 day ");
Title = " ..:: duy ::.. - Filter of Stock " + " " + FullName() + " " + Date( ) ;
// 4-Day-Range Switch
prev=AMA2(C,1,0);
d=IIf(C>Ref(Max(Max(H,Ref(H,-20)),Max(Ref(H,-10),Ref(H,-15))),-1),Min(Min(L,Ref(L,-20)),Min(Ref(L,-10),Ref(L,-15))),
IIf(C<Ref(Min(Min(L,Ref(L,-20)),Min(Ref(L,-10),Ref(L,-15))),-1),Max(Max(H,Ref(H,-20)),Max(Ref(H,-10),Ref(H,-15))),PREV));
a=Cross(Close,d);
b=Cross(d,Close);
state=IIf(BarsSince(a)<BarsSince(b),1,0);
s=state>Ref(state,-1);
ss=state<Ref(state,-1);
sss=state==Ref(state,-1);
col=IIf(state == 1 ,51,IIf(state ==0,4,1));
Plot(C,"",Col,128);
Buy=s;
Sell=ss;
PlotShapes( shapeUpArrow * s ,6,0,L);
PlotShapes( shapeDownArrow *ss ,4,0,H);
dist = 0.8*ATR(10);
dist1 = 2*ATR(10);
for( i = 0; i < BarCount; i++ )
{
if( Buy )
{
PlotText( "\nBuy:" + L[ i ] + "\nT= " + (L*1.005) + "\nSL= " + (L*0.9975), i, L[ i ]-dist, colorGreen, colorWhite );
}
if( Sell )
{
PlotText( "Sell:" + H[ i ] + "\nT= " + (H*0.995) + "\nSL= " + (H*1.0025), i, H[ i ]+dist1, colorRed, colorWhite );
}
}
Buy = ExRem(Buy,Sell);
Sell = ExRem(Sell,Buy);
if ( LastValue(Buy)==1)
{
quantity=2;
orderId=placeOrderFuture("MCX", "FUTCOM", ChartSymbol, "BUY", "INTRADAY", "MARKET", quantity, 0, defaultTriggerPrice(), "19-APR-2018", defaultStrategyId(), defaultComments());
//orderId = placeOrderUsingParams(tradeType, AT_ORDER_TYPE, AT_QUANTITY, buyPrice, defaultTriggerPrice(), 1);
}
if ( LastValue(Sell) == 1 )
{
quantity=2;
orderId=placeOrderFuture("MCX", "FUTCOM", ChartSymbol, "SELL", "INTRADAY", "MARKET", quantity, 0, defaultTriggerPrice(), "19-APR-2018", defaultStrategyId(), defaultComments());
//orderId = placeOrderUsingParams("SELL", AT_ORDER_TYPE, AT_QUANTITY, sellPrice, defaultTriggerPrice(), 1);
}

Answer 1

LastValue documentation
With if statements, you need to specify a specific bar. And according to the documentation, LastValue may look into the future. I can't say for sure what's happening with your code, but the loops/if/switch can be tricky. This tutorial Looping in Amibroker might give you some insights into how they work.
You may try SelectedValue instead. If you haven't got any bars selected, it automatically defaults to the last bar. I use this for my realtime trading.
bi = SelectedValue(BarIndex());
if(Buy[bi])
{
...
}
On an unrelated note, your text plots aren't going to plot unfiltered signals, put your ExRem code under your initial Buy and Sell conditions.