# PRC_HalfTrend | indicator
# 10.03.2017
# Ported by Mobius Apr 2020

input Amplitude = 3;
# 3


def lowpricei;
def highpricei;
def lowma;
def highma;
def barindex = barNumber();
def nexttrend;
def maxlowprice;
def trend;
def minhighprice;
def up;
def down;

plot halftrend;

lowpricei = Lowest(low, Amplitude);
highpricei = Highest(high, Amplitude);
lowma = average(low, Amplitude);
highma = average(high, Amplitude);
if barindex > Amplitude and
nexttrend[1] == 1
{
maxlowprice = Max(lowpricei, maxlowprice[1]);
trend = if highma < maxlowprice[1] and close < low[1]
then 1
else trend[1];
nexttrend = if highma < maxlowprice[1] and close < low[1]
then 0
else nexttrend[1];
minhighprice = if highma < maxlowprice[1] and close < low[1]
then highpricei
else minhighprice[1];
}
else if nexttrend[1] == 0
{
minhighprice = Min(highpricei, minhighprice[1]);
trend = if lowma > minhighprice[1] and close > high[1]
then 0
else trend[1];
nexttrend = if lowma > minhighprice[1] and close > high[1]
then 1
else nexttrend[1];
maxlowprice = if lowma > minhighprice[1] and close > high[1]
then lowpricei
else maxlowprice[1];
}
else
{
maxlowprice = maxlowprice[1];
trend = trend[1];
nexttrend = nexttrend[1];
minhighprice = minhighprice[1];
}
if trend == 0
{
up = if trend[1] <> 0
then down[1]
else Max(maxlowprice[1], up[1]);
down = 0;
}
else if trend[1] <> 1
{
down = up[1];
up = 0;# up[1] este era el error
}
else if trend == 1
{
down = Min(minhighprice, down[1]);
up = up[1];
}
else
{
up =up[1];
down = down[1];
}
if up > 0
{
halftrend = up;
}
else
{
halftrend = down;
}
AssignBackgroundcolor(if close > halftrend then color.dark_GREEN else color.red);

#rec countUpTrend = if up and !up[1] then 1 else if up then countUpTrend[1] + 1 else 0;
#rec countDownTrend = if !down and down[1] then -1 else if !down then countDownTrend[1] - 1 else 0;
#plot data = if countUpTrend > 0 then countUpTrend else countDownTrend;

#AssignBackgroundColor(if data > 0 then Color.BLUE else if data < 0 then Color.RED else Color.CURRENT);

#AssignBackgroundcolor(if close > halftrend then color.dark_GREEN else color.red);

p.s. i originally wrote a much longer intro to this request but when i hit send, i was told my title was too long and i lost the whole thing.  that original title only had 8 words in it, as per your stated max.  if 8 is too many, it's a real pain to follow the rules and get smacked around even so.  sigh.