Мой вопрос о чертеже линейной регрессии .
В примере в документации используется фиксированная длина (100), и поэтому:
- смещение вправо на каждом новом баре
- постоянной ширины (здесь 100 баров)
Я пытаюсь запустить его с определенного момента времени (x баров с этого момента или bar_index или datetime ...), так что:
- он продолжает расширяться на каждом новом баре
- , но начальная точка остается в том же месте (пока мы не изменим его в настройки).
Это означает, что длина (входная) будет динамика c и будет увеличиваться на каждом новом баре .
Я получаю следующую ошибку: Pine cannot determine the referencing length of a series. Try using max_bars_back in the study or strategy function.
Возможно ли это сделать?
Вот код
//@version=4
study("Linear Regression", shorttitle="LinReg", overlay=true)
upperMult = input(title="Upper Deviation", defval=2)
lowerMult = input(title="Lower Deviation", defval=-2)
useUpperDev = input(title="Use Upper Deviation", defval=true)
useLowerDev = input(title="Use Lower Deviation", defval=true)
showPearson = input(title="Show Pearson's R", defval=true)
extendLines = input(title="Extend Lines", defval=false)
// ====================================================================
// ====================================================================
// Original parameter (the one that should increments)
// len = input(title="Count", defval=100)
// Unsuccessful attempt : "Starting from given bar_index"
barIndexOfStartingBar = 6392 - 80 // 6392 : Current bar_index, 80 : Offset to the starting bar
len = bar_index - barIndexOfStartingBar
len := nz(len[1]) + 1
// Unsuccessful attempt : "x bars from current bar"
startingPointFromCurrentBar = input(title="Count", defval=80)
len = (bar_index + startingPointFromCurrentBar) - bar_index
len := nz(len[1]) + 1
// ====================================================================
// ====================================================================
src = input(title="Source", defval=close)
extend = extendLines ? extend.right : extend.none
calcSlope(src, len) =>
if not barstate.islast or len <= 1
[float(na), float(na), float(na)]
else
sumX = 0.0
sumY = 0.0
sumXSqr = 0.0
sumXY = 0.0
for i = 0 to len - 1
val = src[i]
per = i + 1.0
sumX := sumX + per
sumY := sumY + val
sumXSqr := sumXSqr + per * per
sumXY := sumXY + val * per
slope = (len * sumXY - sumX * sumY) / (len * sumXSqr - sumX * sumX)
average = sumY / len
intercept = average - slope * sumX / len + slope
[slope, average, intercept]
[s, a, i] = calcSlope(src, len)
startPrice = i + s * (len - 1)
endPrice = i
var line baseLine = na
if na(baseLine) and not na(startPrice)
baseLine := line.new(bar_index - len + 1, startPrice, bar_index, endPrice, width=1, extend=extend, color=color.red)
else
line.set_xy1(baseLine, bar_index - len + 1, startPrice)
line.set_xy2(baseLine, bar_index, endPrice)
na
calcDev(src, len, slope, average, intercept) =>
upDev = 0.0
dnDev = 0.0
stdDevAcc = 0.0
dsxx = 0.0
dsyy = 0.0
dsxy = 0.0
periods = len - 1
daY = intercept + (slope * periods) / 2
val = intercept
for i = 0 to periods
price = high[i] - val
if (price > upDev)
upDev := price
price := val - low[i]
if (price > dnDev)
dnDev := price
price := src[i]
dxt = price - average
dyt = val - daY
price := price - val
stdDevAcc := stdDevAcc + price * price
dsxx := dsxx + dxt * dxt
dsyy := dsyy + dyt * dyt
dsxy := dsxy + dxt * dyt
val := val + slope
stdDev = sqrt(stdDevAcc / (periods == 0 ? 1 : periods))
pearsonR = dsxx == 0 or dsyy == 0 ? 0 : dsxy / sqrt(dsxx * dsyy)
[stdDev, pearsonR, upDev, dnDev]
[stdDev, pearsonR, upDev, dnDev] = calcDev(src, len, s, a, i)
upperStartPrice = startPrice + (useUpperDev ? upperMult * stdDev : upDev)
upperEndPrice = endPrice + (useUpperDev ? upperMult * stdDev : upDev)
var line upper = na
lowerStartPrice = startPrice + (useLowerDev ? lowerMult * stdDev : -dnDev)
lowerEndPrice = endPrice + (useLowerDev ? lowerMult * stdDev : -dnDev)
var line lower = na
if na(upper) and not na(upperStartPrice)
upper := line.new(bar_index - len + 1, upperStartPrice, bar_index, upperEndPrice, width=1, extend=extend, color=#0000ff)
else
line.set_xy1(upper, bar_index - len + 1, upperStartPrice)
line.set_xy2(upper, bar_index, upperEndPrice)
na
if na(lower) and not na(lowerStartPrice)
lower := line.new(bar_index - len + 1, lowerStartPrice, bar_index, lowerEndPrice, width=1, extend=extend, color=#0000ff)
else
line.set_xy1(lower, bar_index - len + 1, lowerStartPrice)
line.set_xy2(lower, bar_index, lowerEndPrice)
na
// Pearson's R
var label r = na
transparent = color.new(color.white, 100)
label.delete(r[1])
if showPearson and not na(pearsonR)
r := label.new(bar_index - len + 1, lowerStartPrice, tostring(pearsonR, "#.################"), color=transparent, textcolor=#0000ff, size=size.normal, style=label.style_labelup)
