input marketOpenTime = 0930;
input marketCloseTime = 1615;

def yesterdaysClose = close(period = "DAY")[1];

def secondsFromOpen = secondsFromTime(marketOpenTime);
def secondsTillClose = secondsTillTime(marketCloseTime);
def marketOpen = if secondsFromOpen >= 0 and secondsTillClose >= 0 then 1 else 0;

rec regularHoursOpen = if (secondsFromOpen >= 0 and secondsFromOpen[1] < 0) or
(getDay() != getDay()[1]) then open else regularHoursOpen[1];

def newDay = if getDay() != getDay()[1] then 1 else 0;

rec regHoursHigh = if newDay then high else if marketOpen then
if high > regHoursHigh[1] then high else regHoursHigh[1] else high;
rec regHoursLow = if newDay then low else if marketOpen then
if low < regHoursLow[1] then low else regHoursLow[1] else low;

def yc = if marketOpen then yesterdaysClose else double.nan;
def o = if marketOpen then regularHoursOpen else double.nan;
def hg = o + (yc - o) / 2;

def gapUp = if yc < o then 1 else 0;
def gapDown = if yc > o then 1 else 0;

def gapRemaining = if gapUp then
Max(regHoursLow - yc, 0) else
if gapDown then Max(yc - regHoursHigh, 0) else 0;

def percentRemaining = 100 * gapRemaining / AbsValue(yc - o);
def gapFilled = if percentRemaining == 0 then 1 else 0;
def halfGapFilled = if percentRemaining <= 50 then 1 else 0;

plot gH = if (gapUp and !gapFilled and marketOpen and !newDay[-1])
then regHoursLow else if (gapDown and !gapFilled and marketOpen and !newDay[-1])
then yc else double.nan;
plot gL = if (gapUp and !gapFilled and marketOpen and !newDay[-1])
then yc else if (gapDown and !gapFilled and marketOpen and !newDay[-1])
then regHoursHigh else double.nan;
plot hGF = if !gapFilled and !halfGapFilled and marketOpen and !newDay[-1]
then hg else double.nan;

gH.SetPaintingStrategy(paintingStrategy.DaSHES);
gH.AssignValueColor(if gapDown then color.darK_red else color.dark_green);
gL.SetPaintingStrategy(paintingStrategy.DASHES);
gL.AssignValueColor(if gapDown then color.darK_red else color.dark_green);
hGF.setStyle(curve.LONG_DASH);
hGF.SetDefaultColor(color.dark_gray);
gH.hideBubble();
gL.hideBubble();
hgF.hideBubble();

declare lower;
input AvePeriod = 10;
input showOnlyToday = YES;

def T1c = (close("$ADVN")*close("$UVOL"))-(close("$DECN")*close("$DVOL"));
plot T1 = if showOnlyToday and getDay()==getLastDay() then T1c else if !showOnlyToday then T1c else double.nan;
T1.setDefaultColor(color.red);
def TAvec = average(T1,AvePeriod);
plot TAve = if showOnlyToday and getDay()==getLastDay() then TAvec else if !showOnlyToday then TAvec else double.nan;
TAve.setDefaultColor(color.white);

plot zero = 0;
zero.setDefaultColor(color.yellow);

def U = close("$UVOL");
def D = close ("$DVOL");
def DVOL = U - D;