How can I use the linear regression as a filter in my own strategy?

[EveryDayBetter]

Hello. How can I code that my indicator only give a signal, when the price is under the regression line (green line in the middle)? Do you have any idea?

https://bilderupload.org/bild/534488729 ... 009167-111

[processingclouds]

It would be helpful , if you have the indicator code to draw the line already and than we can guide you on how to implement it as a strategy.

[EveryDayBetter]

Thank you for your help. The strategy should also give buy signals, when the price is in the lower deviation and the Pearson's R (between 0 and 1) is over 0,8 ;)

I would like to combine it with a simple moving average strategy as a filter.

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//@version=5
indicator("Moving Average Crosses", overlay=true)

// Get MAs

sma1 = ta.sma(close, 21)
sma2 = ta.sma(close, 50)

// Get crosses
maCrossOver = ta.crossover(sma1, sma2)
maCrossUnder = ta.crossunder(sma1, sma2)

// Draw MAs
plot(sma1, color=color.green)
plot(sma2, color=color.red)

// Draw Crosses
bgcolor(maCrossOver ? color.green : na)
bgcolor(maCrossUnder ? color.red : na)

And here comes the script for the linear regression from tradingview:

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//@version=5
indicator("Linear Regression Channel", shorttitle="LinReg", overlay=true)

lengthInput = input.int(252, title="Length", minval = 1, maxval = 5000)
sourceInput = input.source(close, title="Source")

group1 = "Channel Settings"
useUpperDevInput = input.bool(true, title="Upper Deviation", inline = "Upper Deviation", group = group1)
upperMultInput = input.float(2.0, title="", inline = "Upper Deviation", group = group1)
useLowerDevInput = input.bool(true, title="Lower Deviation", inline = "Lower Deviation", group = group1)
lowerMultInput = input.float(2.0, title="", inline = "Lower Deviation", group = group1)

group2 = "Display Settings"
showPearsonInput = input.bool(true, "Show Pearson's R", group = group2)
extendLeftInput = input.bool(false, "Extend Lines Left", group = group2)
extendRightInput = input.bool(true, "Extend Lines Right", group = group2)
extendStyle = switch
    extendLeftInput and extendRightInput => extend.both
    extendLeftInput => extend.left
    extendRightInput => extend.right
    => extend.none

group3 = "Color Settings"
colorUpper = input.color(color.new(color.blue, 85), "", inline = group3, group = group3)
colorLower = input.color(color.new(color.red, 85), "", inline = group3, group = group3)

calcSlope(source, length) =>
    max_bars_back(source, 5000)
    if not barstate.islast or length <= 1
        [float(na), float(na), float(na)]
    else
        sumX = 0.0
        sumY = 0.0
        sumXSqr = 0.0
        sumXY = 0.0
        for i = 0 to length - 1 by 1
            val = source[i]
            per = i + 1.0
            sumX += per
            sumY += val
            sumXSqr += per * per
            sumXY += val * per
        slope = (length * sumXY - sumX * sumY) / (length * sumXSqr - sumX * sumX)
        average = sumY / length
        intercept = average - slope * sumX / length + slope
        [slope, average, intercept]
        
[s, a, i] = calcSlope(sourceInput, lengthInput)
startPrice = i + s * (lengthInput - 1)
endPrice = i
var line baseLine = na
if na(baseLine) and not na(startPrice)
    baseLine := line.new(bar_index - lengthInput + 1, startPrice, bar_index, endPrice, width=1, extend=extendStyle, color=color.new(colorLower, 0))
else
    line.set_xy1(baseLine, bar_index - lengthInput + 1, startPrice)
    line.set_xy2(baseLine, bar_index, endPrice)
    na
    
calcDev(source, length, slope, average, intercept) =>
    upDev = 0.0
    dnDev = 0.0
    stdDevAcc = 0.0
    dsxx = 0.0
    dsyy = 0.0
    dsxy = 0.0
    periods = length - 1
    daY = intercept + slope * periods / 2
    val = intercept
    for j = 0 to periods by 1
        price = high[j] - val
        if price > upDev
            upDev := price
        price := val - low[j]
        if price > dnDev
            dnDev := price
        price := source[j]
        dxt = price - average
        dyt = val - daY
        price -= val
        stdDevAcc += price * price
        dsxx += dxt * dxt
        dsyy += dyt * dyt
        dsxy += dxt * dyt
        val += slope
    stdDev = math.sqrt(stdDevAcc / (periods == 0 ? 1 : periods))
    pearsonR = dsxx == 0 or dsyy == 0 ? 0 : dsxy / math.sqrt(dsxx * dsyy)
    [stdDev, pearsonR, upDev, dnDev]
    
[stdDev, pearsonR, upDev, dnDev] = calcDev(sourceInput, lengthInput, s, a, i)
upperStartPrice = startPrice + (useUpperDevInput ? upperMultInput * stdDev : upDev)
upperEndPrice = endPrice + (useUpperDevInput ? upperMultInput * stdDev : upDev)
var line upper = na
lowerStartPrice = startPrice + (useLowerDevInput ? -lowerMultInput * stdDev : -dnDev)
lowerEndPrice = endPrice + (useLowerDevInput ? -lowerMultInput * stdDev : -dnDev)
var line lower = na
if na(upper) and not na(upperStartPrice)
    upper := line.new(bar_index - lengthInput + 1, upperStartPrice, bar_index, upperEndPrice, width=1, extend=extendStyle, color=color.new(colorUpper, 0))
else
    line.set_xy1(upper, bar_index - lengthInput + 1, upperStartPrice)
    line.set_xy2(upper, bar_index, upperEndPrice)
    na
if na(lower) and not na(lowerStartPrice)
    lower := line.new(bar_index - lengthInput + 1, lowerStartPrice, bar_index, lowerEndPrice, width=1, extend=extendStyle, color=color.new(colorUpper, 0))
else
    line.set_xy1(lower, bar_index - lengthInput + 1, lowerStartPrice)
    line.set_xy2(lower, bar_index, lowerEndPrice)
    na
linefill.new(upper, baseLine, color = colorUpper)
linefill.new(baseLine, lower, color = colorLower)
    
// Pearson's R
var label r = na
label.delete(r[1])
if showPearsonInput and not na(pearsonR)
    r := label.new(bar_index - lengthInput + 1, lowerStartPrice, str.tostring(pearsonR, "#.################"), color = color.new(color.white, 100), textcolor=color.new(colorUpper, 0), size=size.normal, style=label.style_label_up)

[processingclouds]

I have combined your two code above, and added code to get the median point and at the end added a boolean isLong to check if it meets : >0.7 Pearson's Value, and close < median line (center line in linear regression) ,

Note: I have commented out close > sma1 and close >sma2, you can add filters as you like

Code: Select all

//@version=5
indicator("Linear Regression Channel", shorttitle="LinReg", overlay=true)

lengthInput = input.int(252, title="Length", minval = 1, maxval = 5000)
sourceInput = input.source(close, title="Source")

group1 = "Channel Settings"
useUpperDevInput = input.bool(true, title="Upper Deviation", inline = "Upper Deviation", group = group1)
upperMultInput = input.float(2.0, title="", inline = "Upper Deviation", group = group1)
useLowerDevInput = input.bool(true, title="Lower Deviation", inline = "Lower Deviation", group = group1)
lowerMultInput = input.float(2.0, title="", inline = "Lower Deviation", group = group1)

group2 = "Display Settings"
showPearsonInput = input.bool(true, "Show Pearson's R", group = group2)
extendLeftInput = input.bool(false, "Extend Lines Left", group = group2)
extendRightInput = input.bool(true, "Extend Lines Right", group = group2)
extendStyle = switch
    extendLeftInput and extendRightInput => extend.both
    extendLeftInput => extend.left
    extendRightInput => extend.right
    => extend.none

group3 = "Color Settings"
colorUpper = input.color(color.new(color.blue, 85), "", inline = group3, group = group3)
colorLower = input.color(color.new(color.red, 85), "", inline = group3, group = group3)

calcSlope(source, length) =>
    max_bars_back(source, 5000)
    if not barstate.islast or length <= 1
        [float(na), float(na), float(na)]
    else
        sumX = 0.0
        sumY = 0.0
        sumXSqr = 0.0
        sumXY = 0.0
        for i = 0 to length - 1 by 1
            val = source[i]
            per = i + 1.0
            sumX += per
            sumY += val
            sumXSqr += per * per
            sumXY += val * per
        slope = (length * sumXY - sumX * sumY) / (length * sumXSqr - sumX * sumX)
        average = sumY / length
        intercept = average - slope * sumX / length + slope
        [slope, average, intercept]
        
[s, a, i] = calcSlope(sourceInput, lengthInput)
startPrice = i + s * (lengthInput - 1)
endPrice = i
var bool createdMedian = false
var line baseLine = na
if na(baseLine) and not na(startPrice)
    baseLine := line.new(bar_index - lengthInput + 1, startPrice, bar_index, endPrice, width=1, extend=extendStyle, color=color.new(colorLower, 0))
    createdMedian := true
else
    line.set_xy1(baseLine, bar_index - lengthInput + 1, startPrice)
    line.set_xy2(baseLine, bar_index, endPrice)
    na
    
calcDev(source, length, slope, average, intercept) =>
    upDev = 0.0
    dnDev = 0.0
    stdDevAcc = 0.0
    dsxx = 0.0
    dsyy = 0.0
    dsxy = 0.0
    periods = length - 1
    daY = intercept + slope * periods / 2
    val = intercept
    for j = 0 to periods by 1
        price = high[j] - val
        if price > upDev
            upDev := price
        price := val - low[j]
        if price > dnDev
            dnDev := price
        price := source[j]
        dxt = price - average
        dyt = val - daY
        price -= val
        stdDevAcc += price * price
        dsxx += dxt * dxt
        dsyy += dyt * dyt
        dsxy += dxt * dyt
        val += slope
    stdDev = math.sqrt(stdDevAcc / (periods == 0 ? 1 : periods))
    pearsonR = dsxx == 0 or dsyy == 0 ? 0 : dsxy / math.sqrt(dsxx * dsyy)
    [stdDev, pearsonR, upDev, dnDev]
    
[stdDev, pearsonR, upDev, dnDev] = calcDev(sourceInput, lengthInput, s, a, i)
upperStartPrice = startPrice + (useUpperDevInput ? upperMultInput * stdDev : upDev)
upperEndPrice = endPrice + (useUpperDevInput ? upperMultInput * stdDev : upDev)
var line upper = na
lowerStartPrice = startPrice + (useLowerDevInput ? -lowerMultInput * stdDev : -dnDev)
lowerEndPrice = endPrice + (useLowerDevInput ? -lowerMultInput * stdDev : -dnDev)
var line lower = na
if na(upper) and not na(upperStartPrice)
    upper := line.new(bar_index - lengthInput + 1, upperStartPrice, bar_index, upperEndPrice, width=1, extend=extendStyle, color=color.new(colorUpper, 0))
else
    line.set_xy1(upper, bar_index - lengthInput + 1, upperStartPrice)
    line.set_xy2(upper, bar_index, upperEndPrice)
    na
if na(lower) and not na(lowerStartPrice)
    lower := line.new(bar_index - lengthInput + 1, lowerStartPrice, bar_index, lowerEndPrice, width=1, extend=extendStyle, color=color.new(colorUpper, 0))
else
    line.set_xy1(lower, bar_index - lengthInput + 1, lowerStartPrice)
    line.set_xy2(lower, bar_index, lowerEndPrice)
    na
linefill.new(upper, baseLine, color = colorUpper)
linefill.new(baseLine, lower, color = colorLower)
    
// Pearson's R
var label r = na
label.delete(r[1])
if showPearsonInput and not na(pearsonR)
    r := label.new(bar_index - lengthInput + 1, lowerStartPrice, str.tostring(pearsonR, "#.################"), color = color.new(color.white, 100), textcolor=color.new(colorUpper, 0), size=size.normal, style=label.style_label_up)
    
sma1 = ta.sma(close, 21)
sma2 = ta.sma(close, 50)
plot (sma1)
plot (sma2)
pointOfMedian = s * ta.barssince(createdMedian) + i
isLong = pearsonR >= 0.7 and close < pointOfMedian // and close > sma1 and close > sma2

if isLong
    y = label.new(bar_index,low,"LONG",color=color.green, style=label.style_label_up, textcolor=color.black)
    label.delete(y[1])

[EveryDayBetter]

Thank you very much, it looks pretty good. I have 2 questions.

I've got the error message:

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The variable 'y' is declared in local scope, which may not be executed at every update. So, obtaining its historical values may lead to unexpected results.

for the line

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label.delete(y[1])

What can I do to avoid unexpected result in historical values?

Is there a special reasion that you have choosen 0.7 for the Pearson's Value or can I change it to 0.8?

[processingclouds]

Change the last lines of code as follows:

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var label y = na
if isLong
    y := label.new(bar_index,low,"LONG",color=color.green, style=label.style_label_up, textcolor=color.black)
    label.delete(y[1])

We added definition of variable y in parent scope and than changed the declaration to := from =

This will fix the scope warning messages.


There is no special reason, its easier to test for me at 0.7 as my chart was showing 0.7835 value, so if i used 0.7 to check to make sure LONG shows up.

[EveryDayBetter]

Thank you, there is no warning message anymore ;)