Avec le code ci-dessous, tu obtiendras la valeur du premier point de la régression linéaire (courbe en jaune, soit où est localisé le point jaune).

//PRC_Std and Ste LinRegChannel | indicator
//Standard Deviation and Standard Error
//Linear Regression Channel
//12.03.2019
//Nicolas @ www.prorealcode.com
//Sharing ProRealTime knowledge

defparam drawonlastbaronly=true
defparam calculateonlastbars=1000
// --- settings
lookback= 20 //channel period
// --- end of settings

sumx = 0
sumy = 0
sumxy = 0
sumx2 = 0

for cmpt = lookback downto 0 do
tmpx = cmpt
tmpy = close[cmpt]
sumy = sumy+tmpy
sumx = sumx+tmpx
sumx2 = sumx2 + (tmpx*tmpx)
sumxy = sumxy + (tmpy*tmpx)
next

n = lookback+1

if (sumx2 = sumx * sumx) then // protection to avoid infinite values
b = sumxy - sumx * sumy
else
b = (n * sumxy - sumx * sumy) / (n * sumx2 - sumx * sumx)
endif
a = (sumy - b * sumx) / n

drawsegment(barindex[lookback],a+b*lookback,barindex,a+b*0) 

drawpoint(barindex[lookback],a+b*lookback,3) coloured("yellow")

return linearregression[lookback] coloured("red"), a+b*lookback coloured("yellow")

Sinon, il y a aussi cette alternative en utilisant les 2 fonctions de probuilder : linearregression et linearregressionslope

k = 20 // à ajouter en variable dans la configuration
dpok2=DPO[k*2](close)

if dpok2=dpok2[1] and dpok2[1]=dpok2[2] and dpok2[2]<>dpok2[3] then
start=1
endif

if start=1 and start[1]=0 then
StartIndex = Barindex
Endif

If barindex-k+1 = Startindex then
b=linearregression[k](close)
a=linearregressionslope[k](close)
y=b-a*(k-1)
Drawsegment(Startindex,y,barindex,b)Style(dottedline2,4) Coloured("green",255)
endif

return